AVG, OBP, or OPS for Fantasy Leagues?

Title: AVG, OBP, or OPS for Fantasy Leagues?
Date: August 10, 2009
Original Source: The On Deck Circle
Synopsis: I took a look at how value for players fluctuates depending on if AVG, OBP, or OPS is the rate stat used in fantasy leagues. While most use AVG, I’m a proponent of OPS myself.

With the Fantasy Baseball season beginning to wind down for those not in contention, most leagues have begun discussions about what changes should be made for next year. With my 5×5 Roto League lead now up to a disgusting and insurmountable 14.5 points (runs is the only category I’m not top-4, OBP the only other I’m not top-3), people in my league have been especially active with these discussions.

Among talks of more keepers, new rules for the cost of keepers (e.g. do you keep them at the same price you paid, +10%, +$5, etc), and increased roster sizes, one change has me thinking hard and researching.

This year we chose to go with OBP over AVG, because it’s generally a much better statistic in evaluating a player’s value. To some effect, it has been successful – high-OBP players are more regularly featured, and there is a better sense that available fantasy players are actually less valuable baseball players. Still though, this improvement could be taken a step further. While possibly difficult, could a fantasy league use OPS (On Base Plus Slugging) in place of AVG or OBP?
 More after the jump!
OPS is one of my favorite offensive stats. Especially when controlled for league and park factors (OPS+), it is one of the most telling offensive statistics, and is easy to calculate if you have a player’s “slash line” (AVG/OBP/SLG). OPS takes the improvement OBP makes on AVG (times on base instead of just hits), and accounts for the value of extra-base hits (slugging). In real baseball terms, this is a strong improvement, and it is more predictive (0.35 R-squared) than batting average (0.18 R-squared).

In fantasy terms, there are a few issues. First, it double-counts home runs. Second, it is not a readily available statistic. Most ‘player cards’ or snapshots don’t include it, and television stations are just beginning to display it during broadcasts. This can be both annoying and less fun, as you lose the ability to evaluate on the fly while watching a game and engage in random fantasy discussions. While these are small concerns, they are objections fantasy players may have.

As we continue to discuss the possible change, I thought I’d take a look at some of the players whose value would see the biggest increase if we made the change. Essentially, this is the size of the OPS-OBP gap, or, more simply, slugging percentage. I also divided OPS/OBP to further show the effect, since a high slugging percentage will do less for someone who already has a high OBP (Adam Dunn) than someone with a low one (Hank Blalock). I also showed batting average, to further examine OPS in place of AVG. The top- and bottom-15 are shown.


It is fairly obvious whom this helps and hurts. Rather, it is clear which player types get more fantasy value from this system. Sluggers who generally don’t walk as much and players who hit a lot of doubles are helped the most. Blalock sees a huge jump due to his atrocious OBP and the fact that everything he hits goes for extra bases. The message from these players is that if you’re going to get on base less often, you better go further when you do. Or something like that. At the bottom we see pop-less players, which can include both players without much power (Jason Kendall), or players who walk a lot but don’t hit many extra base hits (Nick Johnson). Understandably, a lot of high-SB players are found here, but their fantasy value comes from the stolen bags anyway.

For those in traditional leagues, this graphic shows the top- and bottom-15 in terms of OPS value over AVG.


Here, sluggers of any kind see a huge jump in their value, while players who primarily hit singles and/or don’t walk at all take a big hit (generally the stolen base studs). Ichiro essentially loses most of his fantasy value here, which is probably a flaw of OPS since he is clearly a useful commodity. But there’s no real secret why hitting the long ball gets you attention and money – it truly is a more valuable play than a single. This is highlighted here, and I strongly feel that some other metric should be used in place of batting average for fantasy purposes. After all, fantasy is supposed to reflect the game as closely as possible, and it has long since been accepted that OPS is a better stat than AVG.

I’m not sure what we’ll do for my league yet. I’m the Commissioner (and the soon-to-be back-to-back defending champion), and I’m leaning towards OPS, but I guess a lot will come down to Yahoo’s availability of OPS and how the league feels in the offseason.

I’m also a loser…on…Twitter. You can follow me here, but there’s not a whole lot of action.

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