I was asked the following question on Twitter yesterday, and gave the requisite response below in short form as Twitter will only allow.
Not always teachable. Some of it is just hard-wired. RT “@AR0D_: how long does pitch recognition take to develop?”— Jeff Moore (@jeffmooreBP) September 3, 2014
Twitter is great for certain things, but it's not great at allowing someone to expand on the answer to a good, solid question like this.
Pitch recognition is one of the harder things to determine when scouting, and has been the downfall of more than a few supremely talented hitters over baseball history. Some players are naturally able to recognize pitches out of the pitcher's hand. It's neurological, and something in the way their brain works allows them to be able to see things that other hitters can't.
Some players, on the other hand, never get the hang of it and it limits their career despite natural talent. Looking back at old prospect lists, there are tons of names of players who cause us to chuckle now at their ranking at the time. Often times, the reason they didn't make it wasn't a mis-evaluation on the part of scouts. It was that they never learned to recognize pitches at the major league level.
The reason for this is that pitch recognition is very difficult to teach and learn. There are drills that can be done to make marginal improvements, but there isn't really much room for significant gain in this area. Hitters can get better by refining their swing mechanics, getting stronger, etc., but it is difficult to make more than incremental gains in terms of being able to recognize pitches.
One thing that does allow players to get better is simply experience. There are few, if any, hitters, who look good the first time they see a big league-caliber breaking ball, but after seeing a few thousand of them some learn to handle it better. Others, however, never learn to identify that pitch, or others.
So why can't we tell this as a player is coming up the ranks?
There are a few reasons. One is that sometimes we can tell, and yet scouts believe that a player has a chance to be a productive player anyway. Starling Marte of the Pirates is a good example. He struggles mightily against sliders from right-handed pitchers. Here is his swing rate against breaking balls from right-handed hitters during his career:
That bottom right corner shows just how often Marte swings at breaking balls down and away out of the strike zone, where he couldn't do any damage with them anyway. And this chart shows just how little damage he does with them:
Essentially, if you bury a breaking ball low and away to Marte, he'll swing at it almost half the time and miss on almost three-quarters of those swings.
This isn't to pick on Marte, who is far from the only major leaguer with these sorts of issues, but they also aren't new for the Pirates left fielder. We don't have the Pitch f/x data from his time in the minors, but it would likely signal many of the same tendencies. They wouldn't be as extreme because the quality of pitching he was seeing wasn't as high, but they'd still be there. Potential pitch recognition issues aren't a huge surprise to anyone who scouted Marte as a prospect.
And yet Marte is still a good player. Despite being susceptible to a particular pitch and thus having a pretty easy book for opposing pitchers to get him out with, he does enough damage against left-handers, on fastballs, and with his legs to be a productive major leaguer. His pitch recognition hasn't improved, he's just a good enough player to get away with that flaw.
Not all hitters can say the same. Others just haven't had an issue until they face the best of the best.
For as much that goes into the minor league process, sometimes we simply don't know how a hitter will react to major league pitching until he faces it regularly. There are minor leaguers with big league stuff, but not a lot of them, and they're not nearly as consistent with it or else they'd be in the majors. There are former major league veterans floating around in Triple-A, but if their stuff was good enough, they'd be in the majors too.
We can gather a lot from watching players in the minors, and there are a number of hitters we can rule out right away. Players who struggle with pitch recognition in the low levels of the minors have a major uphill battle to fight in order to hit in the majors. Others can get away with it by taking advantage of fastballs or poor breaking balls, disguising their inability to hit a quality breaking pitch, or more importantly, not swing at one. There are some players whose future we simply can't determine until it is upon us and his flaws are exposed at the game's highest level.
Ultimately, however, while there are some things that a player can do to develop better pitch recognition (with experience being at the forefront), much of it is just neurological. Some hitters can pick up the trajectory of a pitch, the release point, the spin, etc. naturally and some simply can not.