The graph below acts as a detector for Performance Enhancing Drug (PED) users. The subsequent graphs show an obvious user in Ellis Burks; somebody who might have been using steroids in Chili Davis; and a normal career curve for comparison--the great Dick Allen. We'll start with the chart showing the top 10% and the bottom 10% for adjusted career OPS+ only:
A great way to detect an abnormal career progression; the graph uses OPS+ as a proxy to measure overall batting skill. Relative OPS+ is measured by comparing 5-year periods of a player's career. For instance, when 32 is seen on the age axis it represents the player's performance from age 28 through age 32, and age 33 represents ages 29 through 33 and so on. The "relative" part is introduced when all of the player's other five-year periods are indexed to the player's best five-year period. The best 5-year period is set to equal 100 and the rest of the 5-year periods are measured accordingly. The chart above displays the career progression in which 80% of players fit. A couple of things to remember when viewing the chart is that the area between the 10% lines is 80% of all players measured. Additionally, the player's performance is compared to himself, so if Player A has an 85 rating at age 32 and Player B has an 89 rating at the same age, that does not necessarily mean that Player B was a better player; it just means Player B closer to his peak than Player A. Hit the jump to see some new individual player charts, including a borderline Hall of Fame player and a nearly-certain PED user.
Looks very suspicious, If I had to bet on it, I'd say he was a user. While most players with his OPS+ through their 20's saw a decline beginning around age 33, Davis had his highest five year period of OPS+ at age 38. He then saw a steep, immediate decline, and then he was out of baseball. That sounds a ton like Barry Bonds, who we already decided was almost definitely on PEDs. The increases and decreases are not nearly as dramatic as Bonds' were, so I can't say with 100% certainty that he was juiced. However, the general pattern is still there, which means bad news for all those die-hard Chili Davis fans.
Is there any doubt about it? The chart speaks for itself. Burks, like Barry Bonds, saw a huge jump in productivity in his mid-to-late 30's. After being traded to the Giants at age 33, a year after watching Mark McGwire and Sammy Sosa hit baseballs to the moon, his OPS+ jumped 33 points at age 34, and then another 17 at age 35, before declining every year thereafter. That pattern is a hallmark of PED users, and Ellis Burk's line really fits the bill. It also doesn't hurt to look at the time period of his jump in production for corroborating evidence. He also was a new teammate of our staff's favorite juicer, the faux Home Run King himself, Mr. Bonds. Obviously, that's all circumstantial, but it's just another reason why Ellis Burks seems like a user.
There's A Stat For That
There's A Stat For That