Real Time Analytics

Fast And Furious: Baseball’s Best Combinations Of Power And Speed

Steve Mitchell - USA Today Sports

According to StatCast, the Miami Marlins have two of the “toolsiest” outfielders in baseball… and Giancarlo Stanton.

Midway through September, Mike Petriello of introduced a newly available StatCast metric: Outs Above Average (OAA). This is the latest entry in a line of attempts to quantify outfielder effectiveness, which began at route efficiency and graduated to catch probability this season.
Outs Above Average uses the catch probabilities of individual plays to award outfielders with a point value based on the difficulty of the catch. To illustrate, here’s a running catch made by Ender Inciarte of the Atlanta Braves:
With a 9% catch probability, Inciarte’s catch adds 0.91 outs to his OAA.  Had the ball dropped, he would have lost 0.09 outs from his total. For every ball StatCast tracks to the outfield, this metric is updated accordingly. Conceptually, OAA is the StatCast translation of Ultimate Zone Rating (UZR) and Defensive Runs Saved (DRS), which follows the same sort of point awarding/docking system using Baseball Info Solutions data.
Even though we are still in the infancy stages of StatCast, I cannot help but love the idea of “converting” stats into StatCast-speak. StatCast may be at its coolest when tracking the distance of Giancarlo Stanton long balls, but there is something so satisfying about the digestible details of a leaderboard. Now that there exists a UZR-styled StatCast metric, where can we go next? On what new territory can StatCast shed some light?
Bill James of Historical Baseball Abstract fame once coined a stat called the Power/Speed Number. The metric is the harmonic mean of a player’s total home runs and total stolen bases. In equation form, that looks like:
Power/Speed # = 2 x (HR x SB)/(HR + SB)
James rightfully called this statistic a “freakshow” number, since it deals with totals rather than rates and does not really offer anything valuable analytically. However, the “tools” of power and speed are the “loudest” skills of a player’s profile. The Power/Speed Number is like a quantified metric of a player’s excitement factor, which is why – even if it is hardly used or useful – there is just something so fun about it.
For the fun of it, let’s give this freakshow metric the StatCast treatment. To do this, we need specific StatCast numbers to take the place of home runs (power) and stolen bases (speed). Thankfully, maximum exit velocity and sprint speed fit the bill nicely. With that in mind, I collected every player with at least 100 batted ball events (BBE) and at least 10 max-effort runs to create a sample for this new Power/Speed stat.
But wait! James’ Power/Speed Number works because you can calculate a harmonic mean from counting stats. Exit velocity is measured in miles per hour, and sprint speed is measured in feet per second. Conceivably, one could convert everything to MPH, but we would still have a problem: maximum exit velocity is just so much faster than sprint speed. That disparity is true for every player, no matter how strong or how fast. It would be difficult to discern which player really stands out in a leaderboard of this hypothetical metric.

Image titlePatrick McDermott - USA Today Sports

To work around this, I compared all 370 hitters in my sample and allotted percentile rankings in each of exit velocity and sprint speed. Let’s use Mookie Betts to illustrate the method. Betts’ hardest hit ball this season was measured at 111.7 MPH and his fastest sprint was 28.1 feet/second. Compared to other hitters with 100 BBE and 10 max-effort runs, Betts is in the 70th percentile for power and 78th percentile for speed. Plug these numbers into the formula…
StatCast Power/Speed # = 2 x (Max EV x Sprint Speed)/(Max EV + Sprint Speed)
And Betts gets a harmonic mean of about 74%. To simplify, let’s just remove the percent and give him a StatCast Power/Speed Number of 74. That does not mean much without context, of course. Here comes a leaderboard!
Image title
 Mike Trout is up there, so this list has to be good! In all seriousness, though, the top of this leaderboard features several of the most exciting players in the game today. Trout, of course, but also toolsy outfielders like Souza, Puig, Ozuna, and Garcia. The list also includes young and athletic studs like the recently injured Zimmer, Happ, and Bogaerts. Losing Zimmer for the season is particularly heartbreaking, and not just because viewers nation-wide will miss his raw ability. The young centerfielder also possesses one of the best outfield arms in the game, making him a quintessential five-tool player.
And then… Jose Pirela? The San Diego Padres utility player? The 27-year-old journeyman is having a breakout season (122 wRC+) in his limited at-bats for the Padres, though he had the year cut short following a finger injury. Still, his inclusion towards the top of this list was a surprise. Same goes for Hunter Pence, a veteran in a down year (85 wRC+) who showcased the traditional power/speed combo during the sprightlier days of his early career.
Perhaps the issue is that we are using maximum exit velocity, which only requires you to barrel the ball up once to score a potentially elite ranking. What if we instead looked at average exit velocity, which might be a better approximation of “playable” power? If we adjust the formula by substituting Avg EV for Max EV, we get a new leaderboard:
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Ozuna and Garcia reappear on this list, but you also have breakout players (Pham and Altherr) plus tantalizing young talent (Bellinger and Chapman). Dominating this leaderboard like Zimmer in the previous one is Christian Yelich, who continues to be a bedrock of consistency for the Miami Marlins. An all-around talent on offense and defense, Yelich has been worth 4.5 fWAR in three of the past four seasons.
Then there’s Hunter Pence… again. He is 34 years old, but by StatCast metrics he apparently has not lost a step in regard to his running speed or contact quality. Looking deeper into his batted ball profile and plate discipline, the only discernible trends are a diminishing walk rate (7.1%, his lowest since 2010) and an extreme groundball rate (57.1%, the highest of his career and trending upwards each season since 2013). Those two factors might be enough – despite a normal .302 BABIP, Pence only has 29 XBH to date (perhaps as the result of fewer fly balls) and has not been able to find other ways of reaching base. He clearly still has the ability, but he might need a radical change of approach at the plate to make use of his enduring tools.

Image titleFrank Franklin II - AP Photo

The StatCast variation of the Power/Speed Number has a little more utility than James’ formulation, in that is not dependent upon counting stats as basic as homers and stolen bases. At this point, however, it might just be a neat novelty all the same. Ranking players by the sum of their comparative abilities is an informative exercise, but there are better ways to assess the overall value a player brings to the team.
Going forward, StatCast has a ton of potential to bring about more creative and valuable metrics like Outs Above Average. That said, it might be a while before StatCast has enough information to lump everything into a catch-all statistic like WAR. Until then, we can take comfort knowing that – in one awkward formulation of StatCast data – Jose Pirela and Mike Trout are comparable talents.
All statistics are accurate as of Sunday, 9/24 and were obtained, unless otherwise noted, from Baseball-Reference, Baseball Savant, and FanGraphs, respectively. StatCast data, retrieved from Baseball Savant, is accurate as of Thursday, 9/21.

Edited by Kat Johansen, Vincent Choy.

As of 2017, there are four members of the 40-40 club (40 home runs, 40 stolen bases). Which of the four hit the most homers in his respective 40-40 season?
Created 9/25/17
  1. Jose Canseco
  2. Barry Bonds
  3. Alex Rodriguez
  4. Alfonso Soriano

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