Pitching by the Numbers: Grounders and fly balls

Opening day is the season for second thoughts, doubt and recriminations.

I’m all in on my K minus BB model, with a touch of isolated slugging allowed (slugging average allowed minus batting average allowed). This favors ground ball pitchers. And looking at my Friends and Family staff, I am concerned that my WHIP will be too high while remaining confident that the model will keep my ERA relatively low.

Let’s look at what to expect generally from ground ball and fly ball pitchers on those specific batted-ball types.

We’ll start with the ground ball pitchers and with those who, in 250-plus ground balls, allowed the lowest batting average on grounders. Note the small gap between average allowed on grounders and slugging allowed. Almost all these hits are singles. Note the average on grounders is .236. It is hard for grounders to find the holes.

One of the things you notice right away is that there’s a 2013 Royal above at the top of the list for batting average allowed on grounders and another 2013 Royal also listed for highest average allowed on grounders. This lends support to DIPS theory, that defense is largely random on grounders. Hard grounders are obviously more likely to be hits than routine ones (but not necessarily soft ones). But clearly there is some effect and it’s easily weeded out by BABIP data.

Let’s say that for pitchers above with the lowest average allowed on grounders, it’s half skill and half luck. So, roughly, for someone like Cashner, we wouldn’t assume he was lucky because he should have allowed the average rate of hits on grounders (.236 instead of .204) but instead that he should be halfway between his 2013 level and average.

Bottom line, this is marginal WHIP consideration and not really a big impact on ERA since these hits are almost all singles. Here are the unluckiest ground ball pitchers, minimum 250 grounders.

For these guys, assume half luck and half lack of skill, too. Maybe they gave up 6-to-10 more hits than is reasonable to expect. Again, not a big ERA impact since that’s only 6-to-12 total bases.

Now let’s switch our focus to fly balls by looking at pitchers who gave up a minimum 150 fly balls and sorting by lowest slugging percentage allowed.

You also notice that fly ball pitchers give up less hits (these are minimum 150 fly balls, not necessarily making them extreme fly ball pitchers). The average is .172 on these fly balls. But the slugging average is .489. Look how much better/luckier Colon was with his slugging allowed. Colon is not a mixed-league consideration in Yahoo! formats because his K-rate is just not playable. But those betting on his 2013 averages – even in a good park in the right league and on a team with a plus defensive outfield – are going to be disappointed. But we can’t discount Colon’s skill completely. If it’s something like half skill and half running into the wrong hitters, that’s still a lot of demonstrated skill for 2013 Colon. Still, even regressing to the top 15 on this list in 2014 means a 100-point increase in slugging allowed on fly balls.

I’d be more worried about a guy like Minor, who may be above average in limiting damage on fly balls almost entirely due to random factors/luck. Ditto Scherzer and to a lesser extent, Verlander.

Here are the unluckiest/worst pitchers on a minimum of 150 fly balls, sorted by slugging average allowed.

We have some repeaters here from our list of pitchers who had the most doubles per homer. There are bad pitchers on this list, of course, but are they this bad? And what about the good ones: Sale, Iwakuma, Fister and maybe Dickey, Sabathia, Lackey and Tillman. Health permitting, they’re probably due for a positive ERA correction of up to 0.50.