We’re only three days from the expansion of major league rosters. On Sept. 1, all players on a team’s 40-man roster will be eligible to play in the big leagues without an accompanying move. Often times, baseball fans are treated to a sneak preview of teams’ top minor league talent as a result of September call-ups; or they’re surprised by a relatively unknown player who manages to contribute over the season’s final month.

In preparation for this year’s roster expansion, I thought it would be interesting to look back at the greatest-ever September call-ups, defined here as players that made their major league debut during the month of September.

There are, of course, two ways to look at this: The first is to look at players — position players and pitchers — who generated the most value for their clubs during their call-up. The second is to look at players whose careers began as a September call-up and then went on to have great careers.

I’m looking at both. Read the rest of this entry »

On July 18, 2009, Willy Aybar, who had not played in 6 days, who could barely play second base and had hardly proven himself as a hitter, got the start at second against eventual the AL Cy Young winner, Zack Greinke. Aybar went 4 for 4 with a game-deciding double.

Rays manager Joe Maddon told the media the choice to start Aybar had been a deliberate one, a decision based in the front office’s proprietary analysis. I remember the event — reading the post-game interview moreso than seeing the game — because it marked the first time in my baseball-viewing experience where I had seen a lineup decision apparently based according to ground ball and fly ball data.

Entering the 2009 season, Greinke had a 37.9% ground ball rate — making him one of the league’s more extreme fly ball starters (this has since changed). Aybar, meanwhile, finished his short career with a .349 wOBA against fly ball pitchers and a .300 wOBA against ground ball pitchers.

Since that July 18 game, the Rays have continued to be one of the very few teams to game the underappreciated GB-FB splits game. I suspect one of the main reasons for that is that teams — namely managers — cannot easily identify and predict the splits. Today, I would like to put forth a theory that suggests we can identify — with decent success — GB-FB splits after just watching a hitter take batting practice. Here is the theory:

THEORY: Batters with an uppercut swing will succeed more against ground ball pitchers, and hitters with a more level plane will succeed more against fly ball pitchers, and — naturally — hitters who can swing on both planes will have a smaller overall split.

Let’s examine:

NOTE: Many GIFs are under the jump. The page may load slowly.
Read the rest of this entry »

Andruw Jones was having a brilliant career, that is, until he turned 31 years old. Since that point, he’s barely been a league-average player. He went from an all-time great player, to an iffy hall-of-fame candidate.

Read the rest of this entry »

Updated: Thanks to the commentors, especially Evan, for double checking my work. I had an issue in Excel that messed up the results for May and June. Charts have been updated.

For most of 2012, the Baltimore Orioles have been playing over their heads. Well, at least when it comes to their expected win-loss record.

Based on the run differential the team has generated, the O’s have amassed 10 more wins than we would expect based on their Pythagorean winning percentage. The team has outplayed its cumulative expected winning percentage throughout the year and — since April — picked up two additional wins at the end of each month. If they sustain this performance and finish August with at least 10 more wins then their Pythagorean winning percentage would predict, they would be just the third team to do so since 2001 (the 2004 Yankees and the 2007 Diamondbacks are the other two).

Some might point to this glaring discrepancy between Baltimore’s actual winning percentage and Pythagorean winning percentage as evidence that the Orioles cannot sustain their winning ways. Of course, this raises the question of whether we really gain anything from a predictive standpoint heading into September if we focus on a team’s expected winning percentage rather than their actual performance.

The answer based on a review of the past decade seems to be no.

Read the rest of this entry »

There’s a sense that the knuckleball is more prone to the home run. The guys on the MLB Network, while watching R.A. Dickey give up three home runs to the Reds, thought out loud that the lack of spin meant that it would go further upon contact and lead to more bombs. The home run seems to be the source of some of the ‘risky’ label attached to pitchers that use the knuckler. Even physics professor Porter Johnson said in a recent interview that if a knuckleball “doesn’t move, it’s basically a home run.”

As with all conventional wisdom, this link is worth unpacking.

Read the rest of this entry »

The playoffs of the nation’s premier collegiate summer wood-bat league, the Cape Cod Baseball League, began Thursday night. Along with the end of the regular season come the league’s various awards — and one player, left-hander Sean Manaea of both Hyannis and Indiana State, has won not only the league’s Top Pitcher Award but also its Outstanding Pro Prospect Award.

Manaea was excellent this summer, posting an 85:7 strikeout-to-walk ratio in 51.2 innings for Hyannis over nine appearances (including eight starts). Those numbers are preposterous as they sound: the next most strikeouts recorded was Ryan Connnolly’s total of 56 in 51.1 innings. Nor was Manaea’s dominance merely a product of polish or deception: according to the whole internet, he was sitting at 92-96 mph this summer and topping out at 98. There’s now every indication, provided he remains healthy, that Manaea will go in the first round of the 2013 draft.

It certainly seems as though being recognized as the best college prospect in a league that has, of late, produced ca. 200 draftees per year and generally has about 200-250 active alumni in the majors — it certainly seems as though that sort of thing would indicate future success. “How much future success?” one might wonder — or, like the author, wondered slightly earlier this afternoon.

Read the rest of this entry »

Last week, I wrote about some findings regarding in-season fastball velocity loss and how experiencing a loss in different months affects a pitcher’s chances of finishing a season with diminished pitch speed. The general takeaway was that June and July were the most telling months.

But what about velocity gain? We know that, generally speaking, pitchers lose velocity more than they gain it. So while velocity loss isn’t good, it’s to be expected — and starting pitchers seem to be able to deal with that loss better than relievers. Pitchers who can stave off velocity loss (year-over-year change between +/- .5 mph) perform even better. Moreover, if a pitcher gains at least 1 mph on their fastball in a season they are twice as likely to maintain some or all of that gain the following year.

Gaining velocity, while not a guarantee of better performance, is certainly a boon to a pitcher and his organization. But given that velocity varies for all sorts of reasons, when can a team have confidence that the increase they’re seeing is real and sustainable?

Read the rest of this entry »

Jose Bautista came out of nowhere two-and-a-half seasons ago and hit 54 home runs at the age of 29. At a time when most players’ careers are declining, Bautista’s taking off. In fact, his  breakout has been completely unprecedented for someone his age.

Since the start of the 2010 season, Bautista has accumulated more than 18 WAR. In the history of baseball, only 38 hitters* have reached that kind of production during their age-29 to age-31 seasons. The most amazing part of Bautista’s statistical climb is how it was totally unpredicted.

Read the rest of this entry »

I’ve written quite a bit this year on trends in pitcher aging, specifically velocity loss and gain. In the last iteration I focused on the odds of pitchers gaining velocity back after a season where their fastball dropped by at least 1 mph.

In that piece I listed a few pitchers to keep your eye on given that their velocity was down from 2011. In June, I wrote about CC Sabathia for ESPN and noted that the big lefty is likely beginning to “age”, as the odds are quite a bit higher that pitchers over the age of 30 do not gain their velocity back once they’ve lost it.

After thinking about it a while it occurred to me that there is of course the chance that these pitchers will gain their velocity back by the end of the year (as I noted in both pieces). We know that, generally speaking, pitchers gain velocity as the season goes on. Temperatures rise, and so too do fastball velocities. If this is the case I wondered at what point in the season we can say with greater certainty that a pitcher is throwing as hard as he is going to throw. Is there a particular month where a velocity decline is more likely to translate to or predict a full season velocity decline?
Read the rest of this entry »

Some say the new wild card is a gimmick to artificially create drama. Some say it rewards teams for wining their divisions. No matter what you think about the new playoff format, it’s here — and the playoff probability curve we’re used to is suddenly out of date.

Read the rest of this entry »