Be sure to enter the OV Free Agent Contest. It ends when the World Series ends.
The Cubs, along with all the other teams, have several well known prospects playing in the Arizona Fall League (AFL) right now. They're about 10 games into their season and we've been recapping those games here. There are a lot of issues to consider when looking at these stats if you'd like to put them into some kind of perspective.
First, they're against minor leaguers. Second, it's in Arizona and teams tend to send their best hitters while the best pitchers more often than not are not sent. Third, the disparity in talent in is huge. There can be AAA players, or even players who got some MLB playing time, along with guys in A ball. Fourth, the sample sizes are never all that large. For example, Howie Kendrick had about 125 plate appearances in 2005 and that led the league. Only 8 players had 100 at-bats or more.
Calculating plate appearances is a bit difficult given that mlb.com does not list HBP and SF with the final season stats. There may be game logs we could go through, but it's not worth it. All you have are at bats and walks and that's what I've used to calculate PA in the table at the bottom.
The sample size issue alone is a big one. We know that it's not nearly large enough to learn a whole lot about the player that we didn't already know. A good season shouldn't really change our expectations going forward just as a bad season doesn't tell us it's only going to get worse.
Finally, due to the lack of stats available, calculating the exact league offense is difficult. We can come close with what we have, but it is going to be off a bit.
One other small thing, there aren't all that many who have even enough PA to qualify in the league among the league leaders. Playing time is spread around and not given out to who is the more talented players. Teams send their players there to get playing time and expect them to be played. MLB front offices probably have influence over how much certain players play. The league is smaller so being in the top 5 at the end of the short season isn't the same.
In 2005, there were only 42 qualified hitters. If you are 10th, you're only the in the top 25% of hitters in the league that year. A guy who ranked 10th in OPS in the AFL in 2005 would be comparable to someone who ranked 35th at the MLB level.
Despite all of the issues, we can answer unequivocally that yes, AFL stats mean something. They are important and they do tell us something. It's data. Of course it's meaningful.
The question is how meaningful and that's not something I can answer. I can say that we should consider all the issues above, as well as others I haven't thought.
I can only offer an opinion. It's one I offered in the comments recently. I don't believe they're that meaningful. I don't think they really tell us much about the player that we didn't know before. I can say with some certainty that none of the performances by Cubs prospects, whether good or bad, is going to change my opinion of their ability with one possible exception.
Kris Bryant had fewer than 200 plate appearances after being drafted. He could get about 100 in the AFL, which is actually at a level a little above where he has played so far. After the AFL, a considerable amount of his professional plate appearances will be in the AFL. I'd probably only use that information as a tie-breaker if I was in charge. For example, if I was torn between sending him back to High A or AA (or AA or AAA) then his performance in the AFL could affect my decision. I'm doubtful the Cubs front office is torn at the moment and has already decided where he'll begin the 2014 season. If that is the case, you might learn a thing or two, but ultimately the AFL served as a place where he and others could game playing time.
Anyway, below are the top 10 qualified AFL hitters each year from 2005 through 20011. You can get the picture that the stats should be taken lightly, but they do include some very good players too.
Sam Fuld. (dying laughing)