Monday, March 1, 2010

Day 57: Reaching for Steals (Fantasy Baseball Discussion Part 1)


Alright well as many as you've probably gathered already (especially given my 5 part Twins Blog series back a month or so ago), I'm a big baseball fan. Not only that, I'm also a huge fantasy baseball fan, if any of you are asking the following questions: Why?, What's that? Fantasy whatnow? You can probably go ahead and skip today's post, but anyway like I said fantasy baseball and I get along quite well. Its a way for me to bide my time during lulls at work during the summer and obsess over which Outfielder's BABIP is an illusion and which is right on target. For those of you who don't know what Fantasy Baseball (or any fantasy sports really) is, just imagine Dungeons & Dragons, but with sports...that's the basic premise. While not as scoffed at, at its heart its just as nerdy as a bunch of acne bespeckled adolescents sitting around their mom's kitchen table throwing 20-sided dice and talking about Liches and Kobolds, and all of the players of fantasy sports would be lying to themselves if they thought otherwise. For some reason society is more accepting of a roleplaying game (which at the core, Fantasy Sports really are an RPG where you're the manager of a sports team) that involves sports than it is of an RPG involving quests and awkward sexual advances between imaginary characters. I'm not sure why, but I don't care either.

Now that I've settled that its time to talk Fantasy Baseball. This year will be the fourth season of my 5-year keeper league and I'm coming into the year either first or second in the dynasty rankings (depending on who's scoring system is used), along with that I'll be in my two other leagues so you can be there will be more Fantasy Baseball talk as the year rolls on, especially once the season gets underway. Whats the point of me illustrating this? To show that I'm in three very involved leagues and to prop up my self esteem.

So I had a recent discussion with another "so-called" Fantasy Baseball nerd about how to distinguish the value of certain statistics--particularly the Stolen Base. Now the type of league I usually play is a standard 5x5 head-to-head (R, RBI, HR, SB, AVG, W, SV, K, ERA, WHIP), so maybe this discussion isn't valid for all types of leagues, but for this particular type of league it is a noteworthy analysis (at least in my humble opinion). Anyway, we were discussing how SB's translate to contributions in other categories, much as in the same way HR's translate to RBI/R/HR/AVG. After a little back and forth, we decided that the only real (measurable) contribution would be reflected in Runs--but not just any Runs would do. We were concerned solely with runs scored as a direct result of stealing a base, meaning if a player steals a base and is eventually waved around to score. So our question was is that stolen base more valuable than a stolen base that never resulted in a run?

Why is this important info? Why care about what happens besides the stolen base? Well the simple answer is wouldn't you rather have a player on your roster who's steals would eventually lead to more runs than a player who steals a lot, but in garbage time? So we compiled a list of all of the MLB players who stole 30 or more bags in the 2009 season (30 or more just to limit the amount of man hours required to compile this), and the players who met this criteria were (along with their 2009 totals):
  • Jacoby Ellsbury, SB: 70 / R: 94
  • Michael Bourn, SB: 61 / R: 97
  • Carl Crawford, SB: 60 / R: 96
  • Chone Figgins, SB: 42 / R: 114
  • BJ Upton, SB: 42 / R: 79
  • Nyjer Morgan, SB: 42 / R: 74
  • Rajai Davis, SB: 41 / R: 65
  • Matt Kemp, SB: 34 / R: 97
  • Elvis Andrus, SB: 33 / R: 72
  • Ian Kinsler, SB: 31 / R: 101
  • Jimmy Rollins, SB: 31 / R: 100
  • Derek Jeter, SB: 30 / R: 107
  • Bobby Abreu, SB: 30 / R: 96
  • Brian Roberts, SB: 30 / R: 110
  • Juan Pierre, SB: 30 / R: 57
  • Jason Bartlett, SB: 30 / R: 90
From this, a game-by-game breakdown of each of the players stats was performed and a count was kept comparing the number of times a player stole a base and scored a run in a game versus the number of times that player stole a base and did not steal a run (we're calling this SB2R%). A plot of SB2R% is shown below.
So the average of the sixteen players was that 56.4% of the time they stole a base in a game they also scored a run in that game. Which I guess if you think of it, that's about right since most of the steals will be stealing second and I'll float a guess that about half the time a runner gets to second (assuming a non 2-out situation) that they'll score is somewhere in the neighborhood of 50%, and is more-or-less backed up by this link.

So whats the take away here? Well I guess its that the correlation between stolen bases and resulting runs isn't as direct as you'd imagine. It also shows that a few guys who are the prototypical stolen base sources aren't as productive (in terms of run output) on the basepaths as you'd imagine. For instance, look at Ellsbury, only 59% of the 70 steals were actually converted into a run; while that is somewhat impressive, given that the average is 56.4% its somewhat less impressive. Take Ellsbury's 59% and then compare that to someone like Michael Bourn. Michael Bourn's ADP this year is 85 while Ellsbury is getting drafted 19th. What's the deal there? Or why not Rajai Davis (ADP: 162)? I mean here is the direct comparison between these players, where's the 70 and 150 pick disparity coming from?

Jacoby Ellsbury: 624 ABs, .301 AVG, 8 HR, 60 RBI, 94 R, 70 SB
Michael Bourn: 606 ABs, .285 AVG, 3 HR, 35 RBI, 97 R, 61 SB
Rajai Davis: 390 ABs, .305 AVG, 3 HR, 48 RBI, 65 R, 41 SB

Why did I pick Davis? Look at the number of At-Bats, its just over half. So lets pretend for a moment that Davis had 600 ABs and everything extrapolated linearly, which we all know it always does, what would Davis' 2009 line look like then?

Rajai Davis: 600 ABs, .305 AVG, 5 HR, 74 RBI, 100 R, 63 SB

Isn't that worth something? Is this guy really 150 picks worse than Ellsbury? I don't think so...

One last thing, I also took a look at the correlation between the times when a player steals more than one bag in a game which would result in more than one run that game. For example, if Jacoby Ellsbury stole two bags in one game and those steals resulted in 2 runs, then he'd get more credit for that. In the first comparison Ellsbury would only get credit if he scored a run in that game while also stealing a bag, it actually diluted the effect of multiple steal games. The plot below illustrates a comprehensive comparison.


The only major difference between the two plots is that this seems to further credit two players in particular, Chone Figgins & Michael Bourn. Meaning when these guys steal those steals are most often turned into runs.

I guess the point of all of this was to put some doubt into your mind when it comes to these "automatic" stolen base guys like Crawford, Ellsbury and Pierre. I think its worthwhile to look elsewhere if you're targeting a big steals guy, and I know come draft day I'll be looking forward to Rajai Davis in the 10th round much more than I'll be looking forward to Ellsbury in the second.

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