Tuesday, November 25, 2008
Replacement level theory appliedPosted by Paul Singman at 1:01am
Keith Woolner's Value Over Replacement Player (VORP) system, first developed in the late 1990s, has come quite a long way. It has gone from respected within the sabermetric baseball community, to becoming somewhat mainstream—even though it is often mentioned only by traditional stat lovers ridiculing the sabermetric movement.
Whatever the case, you should get familiar with replacement level theory if you're not already. If you know a thing about VORP, I give you permission to jump down to the next section since I am going to briefly describe its methodology.
(V)alue (O)ver (R)eplacement (P)layer. The key thing is understanding what a replacement player is. A replacement player is expected to produce at the replacement player level. The best way I can explain replacement level is by creating the following hypothetical situation: There are 30 teams and only one shortstop per team. (That makes 30 starting shortstops.) No team has a bench shortstop and all non-starting shortstops are placed in a pool from which any team can sign them, but only if its starting shortstop cannot play due to injury or some other reason.
One starting shortstop does get injured, so that team signs the 31st-best shortstop to "replace" its starter. His expected production is replacement level. It is the baseline from which all other production or value should be judged. The difference in production between the starting shortstop and his replacement is the starting shortstop's value over a replacement player.
That is a somewhat simplistic model of how replacement player works. In major league baseball, determining replacement level is not as easy as finding the 31st best shortstop, but that is the general concept. If you would like to read Woolner's original Introduction to VORP, click the link.
My example does resemble a fantasy baseball league closely, so you should begin to see how I am going to translate the concept of replacement player to fantasy baseball, right after I clarify a few things. First, replacement level differs for every position. You would expect more offensive production from a backup first baseman than a backup catcher.
A replacement level player has a way of getting confused with an average level player. Read this comment thread in which Derek Carty participated over at Fantasy Baseball Generals. If you can follow what is being said, the difference between an average player and a replacement level player will never be unclear again.
VORP theory applied
So now you know the concept of the replacement level player. The next step is to apply it to your fantasy baseball league, specifically by adopting a strategy based on what type of players are replacement level in your league. In a fantasy baseball league, replacement level players are those you can simply add from waivers or the free agent pool. They are in abundance and cost nothing to acquire.
Not every fantasy baseball league's replacement level player is the same. In fact, leagues have different levels of replacement players due to two main factors: the number of teams in the league and the number of starting roster positions.
That is not a breakthrough statement. Everyone has realized this, even if they have not stated it as explicitly. You may have participated in leagues where borderline all-stars are free agents and others where you have resorted to adding borderline starting players because everyone else is taken. "Deep" and "shallow" are the mainstream classifications of leagues, and each type of league requires a different general strategy.
Shallow leagues are my favorites against inexperienced opponents because they are most easily exploited. In shallow leagues, it is a good idea to a draft a lot of risky, high-upside players since if they do not pan out, there are plenty of good free agents you can add to replace the underachieving player.
In shallow leagues, having a deep roster of good players is not desirable, because good players are not far off from replacement level players. The goal, then, is to get as top heavy as possible and acquire great players, at the expense of depth. Your depth will come from the free agent pool, which should abound with players good enough to perform admirably when plugged into a starting role.
The way to get a solid group of great players is through trading. Do two-for-one trades where you get the "one." Even three-for-ones and four-for-ones are not out of the question, depending on how shallow your league is. An example of such a trade is Derek Jeter and Dan Haren for Jimmy Rollins, and you are obviously acquiring Rollins. To fill the empty roster spot, you now have the freedom to add somebody from the free agent pool and in this case you'd probably target a pitcher. Since the league is shallow, there should be some good pitchers available for adding. In this way, your team can become filled with elite players that will lead to a championship.
Deep leagues, ones in which there are no good players in the free agent pool, are much tougher to play and cannot be exploited in the same way as shallow leagues. Generally speaking, you should be looking to take fewer risks because there is no abundant free agent pool to fall back onto; instead, you will be left trying to make something out of a barren landscape. Not an easy task. So, taking less risks is a good idea, but with how unpredictable baseball is (especially because of injuries) don't go crazy sacrificing talent to get supposed "safe" players, because there is no such thing.
While having a deep roster is important, I would not trade away elite players to increase depth. Hope that your riskier picks pan out and be very aggressive in free agency to maximize whatever value comes out of there. A lot of things have to go right to win a deep league.
Deep and shallow leagues
Yes, a league can be both deep and shallow at the same time. Some positions can be shallow while others can be deep because of the second factor mentioned above: starting roster positions. Some leagues have two catcher spots while some only have one, for example. In the former league, a replacement level catcher will be significantly worse than his counterpart in the latter. Because of this, you should heavily target catchers in the second league.
This is basically the same concept as position scarcity, where you value certain positions over other others based on talent, but there is a difference between the two.
Position scarcity is all about average production from a position. If shortstops have an average OPS of .800 and second basemen's average OPS is .750, position scarcity would tell you to value second basemen over shortstops. Replacement level theory deals more with talent distribution. If a replacement level shortstop is expected to post a .700 OPS and a replacement level second basemen is expected to put up a .725 OPS, then shortstops would be more heavily targeted since a shortstops would be much harder to replace than a second baseman.
The two strategies do not contradict one another, so you do not have to choose one over the other. Both can influence your rankings and that is what I advocate, a mixture of both.
Paul has been managing fantasy baseball teams for many seasons and writing for THT Fantasy over the past three years. He is currently a student at UPenn welcomes readers' thoughts at his email here or in the comments below.