Comparables

I have discussed the importance of comparable players in this space before. Baseball’s wealth of history provides a statistical reference that no other sport can claim. If you think about how we make player projections, even simple ones not derived from complex statistically algorithms, you will realize that every expectation you have on the future- in baseball or otherwise, really- is an inference based on how things have occurred up to that point. The most relevant question is how we make that inference and how legitimate it is. In other words, what is the process that allows us to make predictions with some accuracy? Certainly, we consider that player’s personal development, such as the expectation that young hitters develop power over time rather than all at once. But that knowledge is not innate; we only learn what a “typical” way for a player to develop is by observing other players. The most common ways for players to develop become understood as trends that other players will eventually follow. Philosophers call this process of induction a black box, where we put in some past knowledge and somehow churn out generalizations about the way of the world. Some say that there has to be constant conjunction between cause and effect for the generalization that comes out of the black box to be valid.

Unfortunately, baseball players are not perfectly uniform and there could never be constant conjunction between two players through every at bat and every play in the field. On the other hand, baseball players have so many recordable plays that it is easy to compare trends in one player’s career to trends in players’ careers who have come before him. The more statistically precise the statistical comparisons, the less margin for error exists in projecting for the future. For instance, if a new second baseman came along and had the exact same results as Roberto Alomar for his first 1000 plate appearances, we would have a pretty good idea how he would most likely develop from that point. Certainly, differences in league, competition, era, ballparks and the like throw off the comparison slightly, but statisticians can make translations that account for those differences. Furthermore, there are thousands of historical players who compare to modern players to different degrees, giving us the ability to weight individual comparisons and the most important correlations (which component stats lead to a high batting average? How does a player develop a power stroke?). Thus, historically comparable players provide an especially useful black box in making inferences about future player performances, both on the individual level and generalized for many players.

In the next couple of columns, I intend to look at a few of the most important Twins players and prospects to see what their most comparable players can tell us about the present and the future. Keep in mind, Baseball Prospectus uses weighted statistical averages of historically comparable players for its PECOTA projections, but these players are correlated at a particular age. This caveat becomes important when I discuss how Justin Morneau is comparable to a younger Richie Sexson. That comparison does not necessarily mean that Morneau will blast hundreds of homeruns in spite of high strikeout totals, because years ago Sexson ran a real risk of washing out himself. Remember that a comparison to a 24 year old Richie Sexson means that Morneau has the relative probability of improving or falling apart that Sexson had at that time. With the benefit of hindsight, we know that Sexson worked out, which tells us something valuable about his skill set, which we may be able to apply to Morneau to an extent. But we cannot assume that a player will approximate the best statistics of his most successful comparable player since there is a persistent risk of falling into the lowest dregs of the guys on the list who induce the “who the hell is that?’ response. Without further adieu, here are some of the things we can tell from historically comparable players.

Joe Mauer- Mauer is the Twins most valuable asset going forward. PECOTA projects his marginal monetary value at almost $66 million over the next five years, but do not be surprised if the Twins get a little bit of a hometown discount, since there is no way Mauer is going to work hard to get out of the Cities. He is the face of the franchise and his low HR totals artificially deflate his value on the open market, although those will probably come with time. Oddly, Mauer’s top ten comparables include Kent Hrbek (for batting average and left-handedness) and Austin Kearns (for youthful success). It is more useful to see his most comparable players: Joe Torre, Bill Freehan, and Ted Simmons; a Hall of Famer, an eleven-time All-Star, and a nine-time All-Star. Torre famously moved out from behind the plate to play full seasons at both first and third, but Freehan and Simmons spent their entire careers behind the plate save for a few games at first. Freehan was out of the league by the time he was 35, but Simmons lasted until 38, a remarkable run for a player with so many innings behind the plate. And as far as power development goes, Torre had his career best in HRs at 25, Freehan at 26, and Simmons at 29, so the 23 year old Mauer has some time left to develop.

Justin Morneau- I mentioned in the introduction that Morneau has Richie Sexson high on his list, which you might consider a strong complement. Temper that sentiment with the knowledge that his most comparable player is the 1985 version of itinerate first baseman Carmelo Martinez, who the Cubs sent out of town when he was only 23- not exactly a ringing endorsement of his future. Even though it seems like Morneau’s strikeouts are an essential part of his profile, something that has a profound effect on his development and current struggles, Martinez was never terribly strikeout prone. True, the mid-80s had less players swinging from their heels and going for the fences on with two strikes, but Martinez was altogether a different player, walking more than he struck out in a couple of seasons. He only played in 100+ games in six seasons, topping out at 21 bombs in 1985, so Morneau has already had at least one better season. Sexson comes next on the list, followed by Paul Konerko, and while both panned out, there were considerable concerns about high K rates for both of them. Strangely, all three players were traded before the end of their age-25 seasons, meaning that the Twins trading Doug Mientkiewicz to keep Justin Morneau may not have been such a no-brainer in the historical context.

Jason Bartlett- Bartlett’s list is actually extremely flattering and provides a strong account for his future. His most comparable player is 2003’s Jerry Hairston when the 23-year old was starting to get on base in the mid .300s and slug around .400- not star stats, but good enough for a slick fielding shortstop. Keep in mind that Hairston was considered a starting second baseman, but did not have the glove to compete with Brian Roberts in Baltimore, eventually shifting to an IF-OF utility role. Bartlett has no trouble fielding, so replicating Hairston’s bat will make him very worthwhile as an everyday starter. Dick Schofield, his number two comp, topped out at .249/.321/.397, but he played a very solid shortstop through his career, and exhibited a decent walk rate through his career despite a poor batting profile. Edgar Renteria also made the top five, but Bartlett’s top comps are littered with guys who were either strong fielders or decent hitters, but never put it all together. That he has already shown the ability to do both more than most of them bodes well for his future.

I will continue my analysis of comparable players with five more Twins and the historical players they resemble later in the week.