Will Happ's and Myers' Recent Performance Hold Up Next Year?

We know a couple of things about Brett Myers and J.A. Happ this year.  Both pitchers had disappointing first halves in 2011.  And both pitchers have enjoyed a resurgence of sorts in the last month and a half.  Happ's spiraling production gave him a plane ticket to AAA Oklahoma City.  Both pitchers came into this season with excessive expectations associated with unsustainably low ERAs in 2010.  However, with a changing team composition after the trade deadline, both pitchers' ERA has improved since August 1.  There is some evidence that the Astros have enjoyed improved defense over the same time frame.  So, that may partially explain the declining fielding independent pitching (FIP) statistic over that period. 

Probably both pitchers will be back in the rotation next season.  Myers has a contract that is likely to keep him in Houston.  Happ is one of the key pieces in the Roy Oswalt trade, and the Astros are likely to give him every chance to show that he is part of the Astros' future.  In a recent comment on a TCB thread, AstrosB wondered whether the recent strong showings by the two ex-Phillies pitchers indicates a rotation revival or whether that is the type of thinking which fooled the Astros last year.  That's a good question.  To shed some light on that question, I will look to see if there are indications of over or under performance in both pitchers' recent work.

Here are the stats we will utilize: (1) Earned Run Average (ERA); (2) FIP, which is a peripheral based statistic, and indicates the equivalent of ERA unaffected by defensive performance; (3) Expected FIP (x-FIP) which shows the FIP result with a normalized HR rate; this is a stat that is better  at predicting future pitching performance than either ERA or FIP; (4) Batting Average on Balls in Play (BABIP), which provides an indication of the extent that the pitcher has gotten lucky or unlucky with batted balls; (5) league average BABIP; and (6) ZIPS projected ERA for each pitcher entering this season, which is displayed as a measure of what some analysts reasonably expected from each pitcher.

The stats will be provided for the full 2011 season so far, and for the period August 1 through Sept. 15 of 2011.

The tables showing these statistics for those time periods are shown at the end of the article.  But here are my conclusions from those results:

• Both pitchers have underperformed their peripherals on the season.  Myers' underperformance is mild, while Happ's results are far worse than his peripheral based stats.  On the season, Happ has a BABIP slightly above league average, and Myers' BABIP is slightly below league average.  These BABIP results are within a reasonable margin around the league average.
• The primary basis for Myers' underperformance on the season is a ERA that is one half run higher than x-FIP, meaning that his HR/flyball rate exceeds a normalized level.  Even assuming that Myers has some inherent vulnerability to HRs, I think there is a reasonable liklihood that he will benefit from a regression toward league average HR/flyball rates.
• The August 1 - Sept. 15 period is a small sample, particularly for Happ who spent part of August in Oklahoma City.  That said, I think the recent improvements are more trustworthy for Myers than Happ.
• Although Myers' ERA improved in the last one and a half months, he still underperformed his peripheral based stats in that period, meaning that his K and BB stats improved more than his ERA.  The ERA for the period is moving closer to the ZIP projection (3.96) and the FIP fell below the ZIPS projected ERA.
• During the last one and a half months, Happ's ERA overperformed his FIP and x-FIP, with the FIP and x-FIP remaining similar to his season to date peripherals.  Happ's BABIP is more than 50 points below the league average for the recent period, leading me to believe that Happ's recent ERA improvement is more than we should expect in the future.  (Myers' BABIP is below the league average for the period too--but by a much smaller margin.)  
• My guess is that both players are capable of achieving the 3.96 (Myers) and 4.50 (Happ) ZIPS ERA projections next year.  But a safer prediction is probably 0.2 higher.  That would be a valuable performance by an innings eater like Myers.  Happ looks like he will have performance closer to a No. 5 rotation starter.

Happ's horrible ERA on the year probably can be traced to some bad luck in the timing of his bad BABIP moments.  Below are the BABIP results by leverage situation for 2010 and 2011.

BABIP: 2011 / 2010

Low Leverage .297 / .271

Medium Leverage .294 / .261

High Leverage .476 / .242

The .476 BABIP in high leverage at bats indicates that batted balls just found a lot of holes when Happ was in critical situations.  Consider the league average BABIP by leverage: low .293; medium .303; high .290.   I have to think that Happ's BABIP in high leverage situations is a fluke.

Below are the tables I promised.