As of the time of this writing, the A's currently sit 6.5 games up on the Rangers for the division, and 3.5 games back of the Red Sox for the #1 overall seed with 12 games left to play. I'm not trying to jinx anything, but Fangraphs' Playoff Odds currently give the A's a 99.6% chance of winning the division. It's looking pretty likely that the A's are going to be locked into either the #2 or #3 overall seed. And since the #2 seed plays the #3 seed in the divisional round, it's looking more or less inevitable that the A's are going to have another first-round matchup with the Tigers, the team that knocked them out of contention last year.
There's a bit of a running narrative that appears on both this site and elsewhere that the Tigers are the kryptonite to the A's offense. The idea is that the A's are an offense that is built around OBP and power but strikes out a lot, while the Tigers rotation is built around striking hitters out. It would seem that the Tigers' greatest strength is the greatest weakness of the A's. But just how much of a difference does that make, especially in a short series?
We live in an age where statistics like strikeout percentage are available at the click of a button. For instance, we know that the A's, as a team, have a 19.1% K rate, which is actually the 11th best mark in the league. We also know that the Tigers have a league-leading 22.9% K rate. But is there a way to calculate what the A's K rate would be against the Tigers?
There are actual ways to calculate the chances of a strikeout in a specific matchup. Let's take a hypothetical player. Let's choose a name at random, let's call him... Sam. Sam strikes out in 50% of his total plate appearances. But he doesn't face the same pitcher every time- over the course of the season, he faces high-strikeout pitchers and low strikeout pitchers, and on average strikes out 50% of the time. Sam isn't very good at baseball. But will he strike out 50% of the time in any given plate appearance, even if he's facing Joe Blanton in one and Pedro Martinez in the other? Clearly, Sam the Terrible Baseball Player will strike out more often against the high strikeout pitcher than the low strikeout pitcher.
Sabermetricians have actually devised a few different methods of calculating the expected strikeout rate in a given matchup. The most well-known of these is called the "Odds Ratio". The Odds Ratio attempts to calculate the theoretical exact rate in a given matchup, using the following formula:
Expected K% = [(Batter K%) * (Pitcher K%)] / League Average K%
The league average K% is about 18.5%, so we can plug the numbers into the formula to try to figure out just how the A's as a team would match up against Tigers pitching.
|Tigers K% (Pitching)
|A's K% (Hitting)
So the against the Tigers as a team, you would expect the strikeout rate to go up sharply, by about 4.5%. What about by individual pitcher?
|Expected A's K%
What is there to conclude from this? We can assume that the A's will strike out more often against the Tigers. But you know what? So does everyone. And even a 10% change in K rate is only one more strikeout every 10 at bats. It's easy to forget that unlike the 2012 A's who set the American League record for strikeouts in a season, the 2013 iteration is actually about the middle of the pack. If the A's do end up facing the Tigers in the first round, expect them to strike out. But it's not as big of a deal as people like to make it out.