September 8, 2005
The Bull in the Pen
In his discussion of the likely NL MVP race shaping up, Joe Sheehan pointed out that if you look at the most prominent contenders--Derrek Lee, Albert Pujols, and Andruw Jones--Lee distances himself from the field in WARP by a vast margin. Looking at the traditional stats, Lee leads the league in batting average, Jones leads in home runs and RBI, and Pujols is second, third and second in those categories, respectively. It's easy to see why those three would be the favorites headed into the final month of the season.
Debates about the NL MVP aside, this discussion highlights the fact that much of the time--in this case with Lee and Pujols--mainstream stats and more advanced metrics like WARP agree in their assessment of players, but some of the time--with Jones--they do not. No one's arguing that Lee isn't having a great season, but there are many players on whom the two categories of stats disagree. Usually these are players not on the margins--Lee is good, Cristian Guzman is bad--but towards the middle of the pack where middling RBI totals can either reveal a talented player who doesn't get many RBI opportunities or a terrible player granted too much leeway in the middle of the lineup. Discerning between the two makes for good fantasy players and better front offices, though a diatribe on the faults of RBIs likely won't win many bar arguments.
In that vein, let's take a look at a group of players who the mainstream fails to value properly: relievers. For example, let's look at the current leaders on each team in saves, the main metric dedicated to those who ply their trade in the late innings. But rather than simply looking at saves, let's see how those relievers perform in two of BP's metrics: Expected wins added over a replacement level pitcher (WXRL) and Adjusted Runs Prevented (ARP). WXRL shows how well a pitcher did given the context of his performance; striking out the side up by one in the ninth is given greater emphasis than turning the same trick in the fifth. However, because it is context-based, WXRL can be altered by usage patterns as well as ability, so we'll also include ARP, the number of runs a reliever prevented over a replacement level reliever, adjusted for other factors such as inherited and bequeathed runners.
Both metrics have their uses depending on what you're trying to measure, but ARP is a better measure of performance regardless of context, so if you're running a team and want to know how a reliever will do if moved to higher-leverage situations, his ARP can stay the same while his WXRL will likely rise or fall more dramatically. Thus, if we're looking to find undervalued relievers who could step into big roles next season, ARP is an excellent place to start.
Here's how baseball's elite firemen stack up, sorted by their current save totals:
PITCHER TEAM SV WXRL ARP Chad Cordero WAS 43 5.636 23.0 Bob Wickman CLE 36 3.506 10.2 Joe Nathan MIN 35 3.434 11.5 Trevor Hoffman SDN 35 2.974 5.6 Todd Jones FLO 35 4.657 27.0 Mariano Rivera NYA 35 3.301 22.5 Brad Lidge HOU 34 3.342 11.0 Danny Baez TBA 34 3.819 19.8 Jason Isringhausen SLN 34 3.104 13.0 Francisco Rodriguez ANA 34 3.885 10.9 Dustin Hermanson CHA 33 4.178 17.6 Billy Wagner PHI 32 3.489 22.0 Francisco Cordero TEX 31 2.956 9.8 Eddie Guardado SEA 31 3.789 11.1 B.J. Ryan BAL 29 2.014 14.3 Derrick Turnbow MIL 29 4.151 20.2 Braden Looper NYN 28 0.968 3.4 Jose Mesa PIT 27 -0.221 2.3 Brian Fuentes COL 26 5.225 18.0 Miguel Batista TOR 25 1.411 1.9 Ryan Dempster CHN 23 3.242 10.4 Tyler Walker SFN 22 -0.172 -6.0 Yhency Brazoban LAN 21 0.699 -19.3 Huston Street OAK 18 3.360 34.2 Mike MacDougal KCA 17 0.796 7.6 Chris Reitsma ATL 15 1.071 6.3 Keith Foulke BOS 15 -0.953 -3.4 Brandon Lyon ARI 13 1.117 -6.2 Dave Weathers CIN 11 3.432 14.9 Ugueth Urbina DET 9 1.777 7.2
Three of these relievers--all likely considered the best reliever on their team since they're the one being used in the closer role the most often--have negative totals in WXRL: they've cost their teams more games than a replacement-level reliever would have. And it's not just that they've been unfortunate in tight situations: four of them have negative ARP totals, most notably Yhency Brazoban who is last in the major leagues in ARP. That's right: the Dodgers used the worst reliever in baseball as their closer for much of the year.
So which teams are the most egregious offenders of misallocation of their resources? Here are the team leaders in saves, RA (minimum 30 games), WXRL and ARP:
TEAM SV RA WXRL ARP ANA F. Rodriguez F. Rodriguez F. Rodriguez Scot Shields ARI Brandon Lyon Jose Valverde Lance Cormier Jose Valverde ATL Chris Reitsma Blaine Boyer Kyle Farnsworth John Foster BAL B.J. Ryan B.J. Ryan B.J. Ryan Todd Williams BOS Keith Foulke Mike Timlin Mike Timlin Mike Timlin CHA D. Hermanson D. Hermanson D. Hermanson Cliff Politte CHN Ryan Dempster Will Ohman Ryan Dempster Ryan Dempster CIN Dave Weathers Matt Belisle Dave Weathers Dave Weathers CLE Bob Wickman Arthur Rhodes Bob Wickman David Riske COL Brian Fuentes Brian Fuentes Brian Fuentes Brian Fuentes DET Ugueth Urbina Kyle Farnsworth Kyle Farnsworth Kyle Farnsworth FLO Todd Jones Todd Jones Todd Jones Todd Jones HOU Brad Lidge Dan Wheeler Dan Wheeler Dan Wheeler KCA Mike MacDougal Andrew Sisco Mike MacDougal Andrew Sisco LAN Yhency Brazoban Duaner Sanchez Duaner Sanchez Duaner Sanchez MIL Derrick Turnbow Derrick Turnbow Derrick Turnbow Derrick Turnbow MIN Joe Nathan Jesse Crain Jesse Crain Jesse Crain NYA Mariano Rivera Mariano Rivera Mariano Rivera Mariano Rivera NYN Braden Looper R. Hernandez R. Hernandez R. Hernandez OAK Huston Street Huston Street Huston Street Huston Street PHI Billy Wagner Billy Wagner Billy Wagner Billy Wagner PIT Jose Mesa Salomon Torres Salomon Torres John Grabow SDN Trevor Hoffman Scott Linebrink Trevor Hoffman Scott Linebrink SEA Eddie Guardado Eddie Guardado Eddie Guardado Julio Mateo SFN Tyler Walker Scott Eyre Scott Eyre Scott Eyre SLN J. Isringhausen J. Isringhausen J. Isringhausen Al Reyes TBA Danny Baez Danny Baez Danny Baez Danny Baez TEX F. Cordero F. Cordero F. Cordero John Wasdin TOR Miguel Batista Pete Walker Jason Frasor Justin Speier WAS Chad Cordero Hector Carrasco Chad Cordero Chad Cordero
Before we dive into some notes about the above lists, let's clarify some of the save situation debate quickly. By stating that teams are misallocating resources by not using their best relievers as their closer, we're assuming that teams view their closer as their preeminent reliever. With some organizations this is not always the case, but with the majority of the league, it is. (When criticizing letting the save rule dictate decisions, we're not saying that pitching the ninth inning isn't more important than pitching the seventh, but rather keeping your best reliever seated in the bullpen in a tight situation in the seventh so that he can protect a three-run lead in the ninth isn't the best way to deploy your resources.) Furthermore, those relievers who find themselves leading their team in WXRL or ARP are likely in line for a closer position in the near future, but not necessarily with their current team. Abusing those differences between performance as measured by WXRL/ARP and saves or ERA--a particularly poor stat when measuring relievers because of the inherited and bequeathed runner scoring rules--is a way for teams to pluck undervalued talent from their competitors.
Now, those notes:
When it comes to bullpens, identifying those pitchers who are performing well is the first step, but identifying which are over- or under-valued in the market is the next. By comparing mainstream stats like saves to more descriptive stats like WXRL and ARP, it's easy to highlight those relievers whose performance is vastly different than the public perception. And if you know that your data is better than that of your competitors, it's easy to snag a few bullpen gems out from under their noses.