The part about questioning Perez' focus reminded me of my wife's colleague Dan Gilbert referring to the "Fundamental Error of Attribution." (Yes, I know he meant Attribution Error, but I always found it more amusing to phrase it the other way around.)

But sports fandom is especially susceptible to applying causes to things that were less "caused" and more "temporally proximal."

Time stamps might be indicative for some pitchers, but you'd have to start with subjective analysis of the pitcher. One pitcher who lacks focus might speed up his delivery while another might slow it down. And when there's a runner on base, variance is a feature, not a bug. Moreover, many a veteran hitter has disrupted a pitcher's rhythm quite deliberately. Time stamps might be the best available data on pitcher focus, but that suggests to me that there's no good data.

Another problem when it comes to measuring focus is that you have to know what the subject of focus is. Golfers talk about 'swing thought' which means focus on a single aspect of your swing to the exclusion of all others. Exclusive focus on one aspect of your delivery (whether a baseball or a golf club) necessarily requires a lack of focus on some other aspect of your delivery. So a predicate question has to be "focus on what"? A pitching coach (or a caddy) might know precisely what a pitcher (or golfer) is or is not succeeding at focusing on, but a scout would need a little inside info to make that judgment.

Great stuff. Keep pushing. Already excited for the next installment.

Could I also suggest frustration or anger? At that age I bowled in a couple leagues, and was fairly good (172 average). But if I had a bad throw which hurt my score I would frequently become unsettled, which would make things even worse. I needed to relax and get back to my routine. It did not happen to the same degree when I was pitching, but I was able to show a marked improvement in my control by slowing down, taking a few extra seconds between pitches to visualize my next pitch.

Talk about Pandora's box. I'm interested to see if you can make something of this.

Now this is the kind of article a math teacher can read at work and not feel guilty about! Interesting stuff.

This is great stuff, Russell.

The idea of changing one's approach when things go wrong made me wonder what part, if any, risk aversion plays in a pitcher's performance when things start going pear-shaped.

You hear a lot from commentators about a guy needing to "trust" his stuff to succeed, but I wonder how often getting shelled on a certain pitch actually leads to an irrational fear of throwing that pitch again (whether it be in the same location or just the pitch type).

I realize this kind of thing is in that murky area between psych and behavioral economics, but I think it'd make a fascinating study.