Reader thebest suggested I take a look at Wade Boggs and how well he did despite (or due to) often taking the first pitch.
Unfortunately, we have pitch-by-pitch data for plate appearances only from 1988 onward, and even then it's not totally complete. We miss the first bunch of years of Boggs' career. But let's see what we can learn from what data we have available. All of this information comes from Boggs' career splits for pitch data.
Firstly, just how often did Boggs really let the first pitch go by?
We can see that he had 367 plate appearances that ended on the first pitch. He had a .360 BA in those PAs, damn good even for Wade Boggs. He had 3418 PAs that ended sometime after the count went to 1-0. Clearly he took the first pitch in those cases. He had another 2905 PAs that ended sometime after the count went to 0-1. We don't know what fraction of these were taken strikes vs swings that resulted in foul balls. Lets examine the two extreme cases:
Imagine that in the 2905 PAs that had a count of 0-1, Boggs took a called strike every single time. That would mean that he took the first pitch a total of 3418 + 2905 = 6323 times, as compared to 367 times that he swung, meaning he swung only 5.5% of the time, which does indeed seem quite low. Imagine, instead, that in those 2905 PAs, he swung and hit a foul ball every time. That means he took the first pitch 3418 times, meaning he swung at the first pitch only 49.0% of the time.
I wish we knew how often he swung, but we just don't have the data available.
If Boggs truly did take the first pitch very often, then pitchers should really have made sure to throw him a strike. However, even if all those 2905 PAs with an 0-1 count were called strikes, they still threw him a strike less often than they threw a ball (as evidenced by the 3418 PAs with a 1-0 count.)
For comparison purposes, let's look at a couple of other players. First, the best comparison for Boggs is Tony Gwynn, in terms of type of hitter and era of career.
Gwynn (again, after 1988) swung at the first pitch in 1009 PAs. He had 3216 more that went to 1-0 and 2571 more that went to 0-1. The ratio of 1-0 to 0-1 PAs is very similar to that for Boggs, but Gwynn clearly swung at the first pitch a lot more. Using the same two types of extreme cases as above, Gwynn swung at the first offering between 14.8% and 52.7% of the time. When I say that Gwynn swung at the first pitch more often, I'm assuming that the two players had a similar ratio of called strikes vs foul balls on the 0-1 counts--and that may not be a valid assumption.
Let's check one more guy: Don Mattingly, who also had a reputation of taking the first pitch. After 1988, Mattingly had 465 PAs that ended on the first pitch. He had 2335 that went 1-0 and 1798 that went 0-1. That's a range of swinging at the first pitch of 10.1% to 49.2%.
All of these quick results ignores stuff like HBP, which obviously affects the total number of times a player swung or didn't swing.
