MLB: Revisiting Small Sample Size Anomalies

In April, about a month into the Major League Baseball season, I wrote a post about some odd baseball statistics that I noticed while perusing fangraphs. I'll give you a chance to follow the link and read the article for yourself ...

Back? Ok good. Two months later and more than half-way through the season I thought it would be interesting to take a look at how those statistics have normalized, or rather IF they had normalized.

1) A.J. Pierzynski's strikeout rate has risen all the way up to 5.4%. That's still the lowest rate among qualified starters and would represent a career low. There are three true outcomes (TTOs) in baseball, outcomes that are fielding independent: strikeouts, walks and home runs. When Pierzynski comes to the plate one of these true outcomes occurs 11% of the time. This also ranks as the lowest rate amongst major leaguers (Juan Pierre is second at 13%). Compare that with Adam Dunn, the king of the TTOs, who experiences a HR, BB or SO in over 53% of his plate appearances.

2) Jack Cust's ISO (or Isolated Power) is still rather low at .115 and he has only managed to hit 3 home runs this season. Both represent career low paces and because of his power drain Cust has posted his first below average wOBA since he joined the A's in 2007.

3) Ever since he hit the disabled list last year with a wrist injury Jason Heyward hasn't looked quite the same. His power numbers match his freshman campaign but he's walking less (11.7% compared to 14.6%) and the balls that he is making contact with are going for hits less often. His line drive rate is very low at around 13% and he's popping the ball up at an alarmingly high rate (22.6%). It just doesn't look like he's hitting the ball well this season and that's a troubling revelation.

4) Carl Crawford's defensive numbers have improved since April but he still holds a negative Ultimate Zone Rating (UZR) and baseball reference's defensive numbers support UZR. It's possible that Crawford has had a hard time adjusting to Fenway Stadium's unique dimensions, but this would be somewhat odd considering Crawford played in the AL East for nearly a decade before joining the Red Sox this year.

5) Jay Bruce's line drive rate has risen up to 16% and his batting average on balls in play has dropped to .297. Those fall in line with his career rates. Normalization indeed.