Masahiro Tanaka is on pace for the greatest rookie pitching season since World War I.

Mark Fidrych in 1976, Fernando Valenzuela in 1981, Dwight Gooden in 1984—by October, Tanaka in 2014 could be the new go-to reference for immediate success to start a career.

His most recent start, on Tuesday night against Toronto, is indicative of his rookie campaign thus far. The Yankees began a three-game series trailing the Blue Jays by 4.5 games in the division; they turned to their new ace in the first contest, and Tanaka didn’t disappoint. After surrendering a home run and two singles in the first inning, Tanaka pitched five scoreless frames, allowing just two more runners to reach scoring position and striking out 10 for the fifth time this year. The best offense in baseball could hardly even make contact, and three runs of support were enough for Tanaka, who earned his league-leading 11^th win.

Just 14 starts into his MLB career, Tanaka is the heavy favorite to win both the American League Cy Young and Rookie of the Year Award—he would be the first to win both trophies in the same year. He also leads two pitching Triple Crown categories (wins and earned run average) and sits just eight strikeouts behind David Price in the third; winning all three would be a first for a rookie and is a feat that has been accomplished almost exclusively by Hall of Famers.

But let’s not get ahead of ourselves and give Tanaka a plaque in Cooperstown just yet. Instead, let’s appreciate just how good he has been for a first-year pitcher. Among qualified rookies, Tanaka’s 1.99 ERA ranks second in the last 100 years, barely behind Scott Perry’s 1.98 mark in 1918. Since the 1969 expansion, though, Tanaka has the best ERA with room to spare, besting Jose Fernandez’s 2.17 from last year. Beyond ERA, Tanaka tops every rookie pitcher from the last century in categories just about every fan can appreciate.

He leads in traditional measures such as win-loss percentage, and at his current pace, he would end the season with 25 wins, breaking the current record of 22 set by Monte Weaver back during the Great Depression. Midway along the metrics continuum, Tanaka has the best rookie marks in WHIP and strikeout-to-walk ratio, and at the most “advanced” end, he holds the all-time lead in ERA+, a metric that is relevant here because it aims to standardize a pitcher’s performance across eras. As a reference for just how unique Tanaka has been, the difference in ERA+ between him and the second-best rookie from the last century (Jose Fernandez) is the same as the career difference between David Price and Oliver Perez.

Tanaka’s excellence has been much needed for the Yankees, who made the Japanese star the fifth-highest-paid pitcher in history before he had ever thrown a pitch in the majors. New York missed the playoffs last year, and Tanaka has been the main factor keeping the middling Yankees in contention so far this season. Take out the team’s 12-2 record in games Tanaka has started, and New York would have a worse winning percentage than the Astros. Besides fellow rookie Chase Whitely, who has pitched well in the last month, Tanaka is the only member of the rotation with a winning record or an ERA better than 4.32.

The Yankees sit near the top of a jumble of 11 teams within six games of a wild card berth, and with three-fifths of the Yankees’ rotation out for at least another month—CC Sabathia until July, Michael Pineda until August, and Ivan Nova until next spring—they will continue relying on Tanaka to keep them afloat in the race. But there’s bad news for Yankee fans: unless Tanaka is an outlier among outliers, he has little chance of duplicating his performance thus far in the season’s second half.

The combination of skill, health, and luck necessary to produce such a dominant stretch of starts is simply too difficult to maintain for an entire season to be done with any regularity. Consider the 50 best first-half pitching performances of the last two decades, sorted by ERA. Only four of these pitchers fared better in the second half of their respective seasons, while a massive portion of the sample—44 of the 50—saw their ERAs rise. (The remaining two are Kevin Brown, whose first- and second-half numbers in 1996 were identical, and Brandon Beachy, whose 2012 season was cut short in mid-June for Tommy John surgery.)

These 50 second-half numbers were still impressive, as would be expected with names such as Maddux, Kershaw, and Clemens populating the list. But these 50 seasons saw an average ERA increase of 1.45 runs between the first and second halves; a similar drop-off for Tanaka would put him in undistinguished company closer to the league average than its lead.

A similarly pessimistic pattern exists for starting pitchers debuting in the MLB after pitching in Japan. Six Japanese pitchers have started more than 25 games as a rookie, and all six of them performed markedly worse in the second half of that first year. Taken as an average, Hideo Nomo, Masato Yoshii, Kaz Ishii, Daisuke Matsuzaka, Hiroki Kuroda, and Yu Darvish accumulated a 3.31 ERA before the All-Star break in their rookie seasons, but that number rose to 4.45 after the break. Each of the six recorded ERAs lower than 4.00 in the first half, but only Nomo bettered that benchmark in the second. And despite winning 64% of their first-half decisions, they had a cumulative losing record in the second half.

Curiously, this trend isn’t present for all first-year pitchers. Per Baseball Reference’s play index, between 1995 (Nomo’s rookie year) and 2013, 42 other first-year pitchers started more than 25 games (first-year pitchers, not all rookies, were used for this comparison to eliminate any potential advantages a pitcher might gain from a short big league stint before his full rookie year).

Unlike with the sample of just Japanese pitchers, this group had a near-even split between first- and second-half performance, with 23 holding a better first-half ERA and 18 a lower mark after the All-Star break (Horacio Ramirez, like Kevin Brown in 1996, had no difference between his two halves). It doesn’t seem that there is something inherently difficult about maintaining success as a rookie; this finding eliminates, for instance, the argument that perhaps first-year Japanese pitchers struggle in the second half because opposing hitters adjust to the new hurlers’ tendencies as the season progresses.

Nor does there seem to be anything inherently difficult about maintaining success when playing outside Japan for the first time. First-year Japanese hitters over the same time frame displayed no similar trend and, as a whole, played equally well in the first and second halves of their rookie seasons.

But combine “rookie pitchers” and “Japanese,” and there is an undeniable pattern. The most likely explanation concerns the pitchers’ transition from the larger rotations in Japan to the five-man staffs in America.

In Japan, not only are regular seasons shorter, meaning pitchers start fewer games each year (Tanaka’s career high was just 28), but starters also typically enjoy five or six days of rest between starts. In their rookie years in the MLB, Japanese pitchers performed much better with that amount of time off. The six full-time starters studied earlier were merely mediocre on the standard four days between starts but improved to above-average with five days of rest and Cy Young-quality when given six days or more.

Hiroki Kuroda and Kaz Ishii as rookies, for instance, were worse than league average with four or five days between starts but turned into Bob Gibson circa 1968 when given more, each holding opponents to just two runs total in four starts on extended rest.

Tanaka, for his part, has had one start with more than five days of rest this year: a gem against the Cubs on April 16 in which he allowed just two hits and struck out 10 in eight shutout innings. The only reason the extra-rest trend doesn’t completely hold for Tanaka is that he’s been pretty dominant on four and five days between starts, too.

This performance difference disappears across Japanese pitchers’ entire careers, indicating that over time pitching in America, they grow accustomed to pitching on less rest. Whether or not rest variations between appearances can help explain Japanese starters’ tendency to fade in their first year with a new pitching schedule is not entirely confirmed, but it’s a start.

Though the last 800 words have all pointed to Tanaka spending August and September struggling to maintain a sub-2.00 ERA or throw a quality start every time on the mound, there is still some room for optimism.

Tanaka allowed just 10 home runs in nearly 400 innings across his last two seasons in Japan, but he’s already given up that many in a quarter of the innings this season. It makes sense that Tanaka might be more homer-prone facing better hitters in the MLB, but the numbers suggest that he has been unlucky in this regard.

It might be heresy to cite home-run-to-fly-ball rates on this website, but I’ll take the risk. The percentage of fly balls hit off Tanaka that have gone for home runs (13%) is quite high, suggesting that it is likely to decrease and that Tanaka will probably start surrendering fewer homers. A 13% rate is by far the worst among any of the top 10 pitchers in ERA this year—most of whom have HR/FB rates hovering around 4 or 5%—and Tanaka allowed only eight earned runs all year that didn’t come from home runs, so imagine—and salivate, Yankees fans—at what he might do once his fly balls start landing short of the fence.

At any rate, it’s clear that general manager Brian Cashman was underselling his new purchase in the offseason when he predicted that Tanaka would be a No. 3 starter. Not many players can make $155 million look like a bargain, but that’s what Tanaka has done so far; he is the team’s undisputed ace, and he’ll remain in that slot even if his ERA rises by 1.45 runs in the second half and he doesn’t one-up Fernandez for the best rookie season in the modern era. And if he can propel the Yankees to at least a wild card berth, New York will almost assuredly have the pitching advantage in the playoffs’ play-in game.

The Tampa Bay Rays have turned into pumpkins. The clock has struck midnight on them this season, and they are guilty of not keeping track of the time. When midnight struck, their glass cleats shattered, and they joined the rest of the pumpkins in Charlie Brown’s pumpkin patch.

In baseball terms, it’s mind boggling that a team that drafted Evan Longoria in 2006 and David Price in 2007 could show such puny production from subsequent drafts. It’s true that the Rays selected Longoria with the third pick and Price with the first and with the exception of the draft after those two haven’t selected higher than 17th since, but their choices in recent years leave much to be desired.

In the drafts from 2008 through 2013 the Rays selected 294 players. Only five of those have played in the majors, none with significant playing time or performance. Only three have played for the Rays. One has played for the Cubs and one for the Marlins following trades.

If not for a disabling injury, one of those players might have become a regular member of the Rays’ lineup. Tim Beckham, a second baseman, was the first pick over-all in the 2008 draft, as Price was in 2007. He played in five September games last season, batting seven times and starting one game at second.

However, he was hurt working out in the off-season and had surgery for a torn knee ligament last Dec. 17. He continues to rehabilitate his right knee on the disabled list.

The Rays were able to draft Longoria, Price and Beckham because their consistently pitiful performances put them in position to select high in the draft.

Those dreadful seasons came in the first of the two distinct phases that have made up their relatively brief history.

Under the planning of the founding owner, Vince Naimoli, one of the worst owners in recent baseball history, they had losing records in each of their first 10 years, reaching 70 victories only once, in 2004, the only year they didn’t finish in last place.

Then came phase II. Under the guidance of a new owner, Stuart Sternberg, and his Wall Street Wonders, the Rays have enjoyed six successive positive seasons, winning 90 or more games five of those six seasons and finishing first, second and third two times each. You don’t get the first over-all pick after those kinds of seasons.

After the 2008 Beckham pick, the Rays have picked 30^th, 17^th, 24^th, 25^th, 21^st and 20^th this year.

On the other hand, there was the 2011 draft. With a collection of compensation choices, the Rays had 10 of the first 60 picks and 12 of the first 89. It would seem with that many selections a team could emerge with a good draft by having a promotion to choose a fan to be blindfolded and put her finger on names on a draft list.

The Rays, though, had their regular drafters make the selections, probably starting with general manager Andrew Friedman, who typically didn’t return calls to discuss that draft and others, and they’re still wondering where they went wrong.

There’s still time for the 10 or 12 players the Rays chose that year to develop into major leaguers, but they haven’t offered much evidence of that likelihood. Outfielder Mikie (sic) Mahtook is the only one in the group who was invited to spring training as a non-roster player and is the only one who has played above Class AA in the minor leagues.

In order of their selection and where they are playing this season (all are in Tampa Bay’s minor league system):

• Taylor Guerrieri, right-handed pitcher, Class AA Montgomery (Southern League) disabled list
• Mikie Mahtook, outfielder, Class AAA Durham (International)
• Jake Hager, shortstop, Class AA Montgomery (Southern)
• Brandon Martin, shortstop, rookie Princeton (Appalachian)
• Tyler Goeddel, third base, Class A Charlotte (Florida State)
• Jeff Ames, right-handed pitcher, Class A Charlotte (Florida State)
• Blake Snell, left-handed pitcher, Class A Charlotte (Florida State)
• Kes Carter, outfielder, Class A Charlotte (Florida State)
• Grayson Garvin, left-handed pitcher, Class AA Montgomery (Southern)
• James Harris Jr., outfielder, Class A Bowling Green (Midwest)
• Granden Goetzman, outfielder, Class A Bowling Green (Midwest)
• Lenny Linsky, right-handed pitcher, Class AA Montgomery (Southern) disabled list

“One thing that hurt them was when they had multiple picks a few years ago,” an executive of another team said, referring to the 2011 draft. “They had all those picks in the top 50 or 60 in the country, and they put a high ceiling on high school kids. That hasn’t panned out.”

Six of the Rays’ first 10 picks and seven of the first 12 were high schoolers, and many are struggling to climb through the minor league system.

Asked if the Rays could benefit from making changes in their scouting and development staff, the executive said, “There are probably some people where if they shuffled the deck they could be better.”

Again, General Manager Friedman did not make himself available to comment on that view.

“When you draft first,” the executive added, “you’re set for a number of years. You have unique opportunities to stock your farm system and create a future nucleus. They did well with Longoria and Price. As they found out, when you draft at the other end of the round it’s not as easy. They’re less than successful.”

As if the Rays’ future may look bleak, their present is even more dismal. Entering Sunday’s games, they had the majors’ worst won-lost record, the only winning percentage under .400. Their standing 13 ½ games from first place was the greatest distance in every division but the National League West, where the Diamondbacks were 15 games from first and the Padres 13 ½.

One executive, who also spoke on the condition of anonymity because he didn’t want to be quoted talking about another team, said the Rays encountered “a perfect storm.”

“Things were lined up” he said, “but haven’t panned out, starting with the starting pitching. “Four of their five starters were out at one time. The team is built around pitching. I’m not sure any team can withstand having four of five starters out, especially a small-market team. The closer didn’t work out either. He’s had a miserable season.”

The Rays signed Grant Balfour to a two-year, $12 million contract after he gained 62 saves and had a 2.56 earned run average for the Athletics the past two seasons.

This season Balfour has gained 10 saves in 12 opportunities but has a 5.88 earned run average and has thrown only 56 percent of his pitches for strikes. He has walked 20 and struck out 22 in 26 innings. He has also lost his job as the closer.

Two starting pitchers remain on the disabled list, Matt Moore out for the season following elbow surgery (Tommy John variety, of course) and Jeremy Hellickson, whose “minor,” to use the Rays’ word, January elbow operation was supposed to cause him to miss six to eight weeks of the season but has kept him out for two and a half months.

Wil Myers, the 2013 American League rookie of the year, is also not ready to return from his injury, a stress fracture of his right wrist he suffered earlier this season. He was hitting only .227 with 5 home runs and 25 runs batted in when he was injured. The Rays expect their right fielder to be in a cast another four or five weeks.

One of Myers’ replacements has been Kevin Kiermaier, the Rays’ 31^st-round choice in the 2010 draft. Kiermaier has played 19 games, batting .352 (19-for-54) with 3 home runs and 4 r.b.i.

C.J. Riefenhauser is the other Rays’ 2008-2013 draftee who has played for them. A 20^th-round pick in 2010, the left-hander relieved twice against the Mets on consecutive weekend days in April, giving up three earned runs in 2 innings. The Mahopac, N.Y., native hasn’t been seen in a Rays’ uniform since.

If teams believe they have the right to decide when to call up players from the minor leagues, why won’t they acknowledge that major league service time is a primary factor, if not the only factor, in determining the call-up date?

The Pittsburgh Pirates’ top officials, for example, in explaining why they are not yet promoting a player, always say the player needs more minor league experience, more plate appearances, more work at an unfamiliar position.

President Frank Coonelly and General Manager Neal Huntington never say, “If we keep him in the minors another few weeks we gain a year in salary arbitration.”

Coonelly and Huntington are not alone in their reticence. None of the clubs speak about the subject with candor. The pattern prompts speculation that the commissioner’s office issues a script for clubs to follow. Interestingly, Coonelly used to be in the position of fashioning scripts for clubs to follow as general counsel for labor in the commissioner’s office.

However, Dan Halem, executive vice president for labor relations, denied that he or his office has anything to do with clubs’ call-up practices.

“We don’t do that,” he said in a telephone interview Wednesday night. “We don’t get involved in when a club calls up a player. That’s a club decision. It’s up to the clubs why they do it, when they do it.”

The Pirates have their system down pat. In the past six seasons they have promoted seven top prospects in a three-week period May 29-June 16. Gregory Polanco’s June 10 call-up fit right in.

Halem said the clubs’ right to determine the timing of the promotion of their players stems from decisions in two grievances, the more prominent being Dennis Lamp vs. the Blue Jays in 1986.

Lamp contended that the Blue Jays didn’t use him in relief in September that season to avoid having his option for 1987 become guaranteed. The arbitrator, George Nicolau, said he wouldn’t tell a manager when to use a player.

The union obviously accepts the clubs’ interpretation of the ruling because it hasn’t challenged the clubs’ promotion practice despite the obvious link between call-up timing and ramifications it has on service time and impact on salary arbitration. Union officials keep saying they are watching, but that’s all they’re doing.

I question the delayed call-ups even if they are permitted because I believe they strike at the integrity of the game. Fans expect teams to do what they can to produce a competitive, if not a winning, team.

That doesn’t mean the Pirates should be expected to match the Dodgers’ $235 million payroll; that’s not realistic, and the fans know it. But if a team has a Gregory Polanco at its Class AAA minor league level and he’s tearing up the league offensively, wouldn’t it be reasonable for the fans to expect the team to call him up to see if he could add a spark and some offensive production?

Yasiel Puig did that for the Dodgers last season even though they didn’t call him up until June 3.

Whenever he is summoned, the young player doesn’t arrive with a guarantee, certainly not with the likelihood of the 2013 Puig production. But if he’s leading his minor league in total bases, hits, runs batted in and runs scored and ranks in the top four in batting average, on-base and slugging percentages and stolen bases, wouldn’t you like to see what he could do in the majors?

He might help his team win some games and even catapult it into the playoffs as a wild-card entrant. But in Polanco’s case, he needed more experience and development. That’s what Coonelly told reporters about two weeks before Polanco suddenly had gained enough experience and development to play major league baseball.

At no time did Coonelly or Huntington say the Pirates were keeping Polanco in the minors to prevent him from qualifying as a “Super Two” for salary arbitration. If Polanco plays in the majors the rest of this season and the entire 2015 and ’16 seasons, he will finish 2016 with two years and 111 days of major league service time.

That total will not make Polanco a “Super Two,” one of the 22 percent of players with more than two years of service but not as much as three. The last player eligible for salary arbitration earlier this year had two years and 122 days.

By the time the outfielder reaches that point of his career, salary arbitration may be moot. Chances are the Pirates will have signed Polanco to a multi-year contract. They offered him one in spring training, reportedly a seven-year deal worth about $25 million. The 22-year-old Dominican said no, thank you.

Had Polanco accepted the contract, it’s possible that the Pirates would have called him up earlier than June 10 because service time would not have been a factor. But then again, there was that lack of experience and development.

Why won’t Coonelly and Huntington say they base their call-up decisions on service time? For the second straight week neither executive returned telephone calls seeking answers to that question. If they had called, they wouldn’t have been forthright anyway.

A Pittsburgh area baseball reporter told me he has never heard Coonelly or Huntington mention service time as the reason for the timing of their call-ups.

Honesty, candor and transparency would go a long way toward letting fans know why the clubs aren’t doing everything they can to make themselves better and worth the price of tickets fans pay to see them play.