It was almost a decade ago on the north side of Chicago when Cubs fans began to turn on their fading superstar Sammy Sosa.
In 2003 Sammy’s WAR had dropped to a pedestrian 2.7, his lowest point since the historic home run race of 1998, according to FanGraphs. With all the bitterness of the club’s catastrophic collapse in the 2003 postseason still lingering, stories portraying Sosa as a clubhouse cancer began filtering out into the local papers. In 2004 Sosa’s value slipped yet again, and things went from bad to worse. By January of 2005 the Cubs front office had had enough and finally traded Sosa to the Baltimore Orioles.
It was about this time that I started hearing a very common complaint about Sosa and the untimeliness of his home runs. Sosa was very unpopular by the time he had been traded, but the sentiment that his long balls were conveniently un-clutch seemed to grow in the ensuing years.
I’ve often wondered how true this was. Individual moments in baseball can leave powerful and lasting impressions about the game we observe on a daily basis. If we see Sosa homer in a blowout on Tuesday, then strike out in a tie game in the ninth on Wednesday, that impression based on a two-day sample can last a lifetime.
Ten years ago, however, I didn’t know about Win Probability Added and Leverage Index. And today we have access to all sorts of wonderful information to gauge “timeliness” at FanGraphs. So I wondered if we could figure the average Leverage Index and Win Probability Added when Slammin’ Sammy launched one onto Waveland Avenue.
The first thing I looked at was the league average Leverage Index and Win Probability when home runs are hit for each year, so we have some idea of what “normal” might be. From 1974 to 2013 the WPA on home runs has remained fairly stable at .13 to .14, dipping to .12 only during the peak years of the steroid era. League Leverage Index for home runs over Sosa’s career bounced around a bit, but averages out to around .96 during that time frame.
We can then compare Sammy’s average WPA and LI on his home runs to those of the league for his entire career:
Sammy Sosa WPA and LI on home runs
|Year||HR||WPA HR||LI HR||WPA HR above average||LI HR above average|
For his career, Sosa’s home runs had an average WPA of .13, which matches the league average almost perfectly. Yet the average LI on his homers was significantly below average at just .92 over the course of his 18 seasons. The weighted average of Sosa’s LI on homers is -0.03 below league average. So as it turns out, Cubs fans may have a legitimate grievance with their controversial right fielder.
I should also note that his low LI on home runs is not simply for lack of opportunity. Sosa’s average LI on plate appearances is a healthy 1.03 for his career.
How does this low LI on dingers compare to other sluggers of the WPA era? If we look at all batters with at least 500 home runs since 1974 (when LI is first available at FanGraphs) we see that Sosa’s .92 is the lowest of them all. Among players with 400 homers, his low showing in average home run LI is bested (worsted?) only by Andruw Jones.
WPA and LI on home runs for players (minimum 500 homers)
|#||Name||HR||WPA HR||LI HR|
|7||Ken Griffey Jr.||630||0.13||0.98|
So how does this happen? What makes Sosa’s average LI on home runs so much lower than a true example of a bona fide clutch slugger like Eddie Murray? Let’s see if we can break this down a bit.
Taking some of the components of Leverage Index to find out how Sosa and Murray’s home run rates compare in each, we start to gain some insight into the differences between the two. We see that Murray on average hit home runs later in the game, averaged more RBI per home run, and did so more often when the run differential was tighter:
I’ll admit, the differences between the averages may appear small, but when we look a bit more closely, we see what a difference it makes. Take the average run differential, for instance. Sammy hit more home runs when his team was down, but he also hit many more when his team was out by at least four runs or more:
Percent of home runs by score
|Name||1-run / tie||Down 2-3 runs||Up 2-3 runs||Down 4+ runs||Up 4+ runs||TOTAL|
Sammy’s poor performance when it “counted” is not limited to home runs. In fact, his overall performance in critical game scenarios is one of the worst, if not the worst of all time. If we look at FanGraphs career “Clutch” leader boards, we see that Sosa rates as the most un-clutch hitter of all qualified hitters (since 1974). Eddie Murray, incidentally, shows up as the 23rd most clutch hitter with the same set of criteria.
Still, Sosa’s knack for hitting long balls when it appeared to benefit only the back of his baseball card is not unique. Other players of the last few decades have shown that same ability, and some have even outdone Sosa. Here are the worst average LI for home runs for all players with at least 100 career homers:
|#||Name||PA||HR||WPA HR||LI HR|
Since 1974, there have been 15 players who have hit just one career home run with a Leverage Index of 0.00. In other words, the only home run of their career was utterly meaningless (assuming they had not hit another home run pre-1974). Knuckleballer Charlie Hough roamed the big leagues for 25 long seasons and had what is potentially the most meaningless home run of them all.
On April 24, 1977, Hough entered the game in relief in the eighth inning of a blowout. With his team up 15-6 with bases empty in the top of the ninth, Hough hit for himself and put his first and only major league baseball into the outfield seats in Atlanta-Fulton County Stadium. The event added exactly 0.00 WPA to his team’s chances of winning the ball game.
Conversely, Edgar Caceres, in his lone season in the major leagues, as a 31-year-old utility infielder for Kansas City, decided that the only home run of his career should really make a difference.
On Aug. 4, 1995 with the Royals down 4-3 in the seventh inning, Caceres entered the game as a pinch runner. He would come to bat in the eighth inning down a run with runners on second and third. The Leverage Index at that point was an astonishing 4.7. Caceres went yard, winning the game for the Royals, earning himself a whopping .50 WPA for his lone career home run.
Biff Pocoroba earns the honor of hittng the homer with the highest Leverage Index. On May 17, 1977, Pocoroba stood at the plate with two outs and the bases loaded in the bottom of the ninth inning. With his team down a run, the leverage index was at a stratospheric 10.98. Pocoroba homered, winning the game for the 9-6, proving that not every Biff is as much a loser as Biff from Back to the Future.
Tony Gwynn ties world-renowned clutch superstar Bobby Murcer for the highest average WPA on home runs for all players since 1974 with at least 100 career long balls. Both players averaged .17 WPA. Former NLCS MVP Cody Ross ranks up as sixth on that list, while Eddie Murray showed up ninth.
Yet, 16-year journeyman outfielder Bill Robinson still beats them all—Murray, Murcer, Ross, Gwynn, et al. Robinson, who hit just 117 home runs from 1966-1983, stands alone as the most clutch home run hitter with an astonishing 1.24 career average LI on his home runs.
References & Resources
Thanks to FanGraphs, Baseball Heat Maps, and Retrosheet.