Stolen Base Opportunities

Stolen bases require a combination of runner speed, aggressiveness, and opportunity, but all too often, we assign all of the credit or blame to runners who either increase or decrease their stolen base totals to their speed. A month and a half into the season, it’s common for runners to be well off of their stolen base pace from last season even if they have not experienced a change in their speed or willingness to steal bases. Before I make any alterations to my expectations for players, I like to take an alternative look at basestealer effectiveness based on their opportunities.

For these purposes, I’ve defined a stolen base opportunity as (1) a plate appearance that (2) features at least one received pitch—i.e. the first pitch was not put in play—where (3) the runner in question is on first base and (4) second base is open. There are many more potential factors I could consider, such as the fact that some plate appearances offer multiple pitches for the runner to steal and expectations of pitch types can affect decision-making. However, I think the simple approach does a fair job of addressing the question at hand.

First, here are the leaders in stolen base rate this season among runners with at least three stolen bases.

Best Stolen Base Rate, 2016
Runner SB Opps SB Rate
Cameron Maybin 3 6 50%
Billy Hamilton 7 14 50%
Starling Marte 12 26 46%
Jarrod Dyson 6 14 43%
Michael Taylor 6 15 40%
Jose Altuve 15 42 36%
Mallex Smith 6 17 35%
Danny Santana 7 20 35%
Jacoby Ellsbury 9 29 31%
Rajai Davis 8 26 31%
Dee Gordon 6 20 30%
Ian Desmond 8 27 30%
Drew Stubbs 7 23 30%

I kept the stolen base requirement low so I could talk about Cameron Maybin, but I’ll save him for the next section. The main player I want to talk about here is Mallex Smith. Smith routinely stole 30-plus bases in the minors, and his slow start to his major league career is pretty much entirely the result of his lack of opportunities. The .290 OBP likely clued you in, but Smith has just 17 stolen base opportunities this season in his 103 plate appearances. His 4.9 percent walk rate is the major culprit, but that rate is well down from his minor league standard that routinely had him above 10 percent. I expect the walks to come for Smith as he adjusts to the league. Meanwhile, his 35 percent stolen base rate is better than Dee Gordon’s last season (30 percent) when he stole 58 bases. Smith may not get to Gordon’s level offensively, but 40 steals per season seems like a reasonable expectation to me.

Next, here are the basestealers with the biggest increases in stolen base rate.

More Aggressive Basestealers, 2016
2015 2016
Runner SB Opps SB Rate SB Opps SB Rate Change
Cameron Maybin 23 143 16% 3 6 50% 34%
Michael Taylor 16 100 16% 6 15 40% 24%
Starling Marte 30 137 22% 12 26 46% 24%
Marwin Gonzalez 4 79 5% 4 16 25% 20%
Danny Santana 8 46 17% 7 20 35% 18%
Rougned Odor 6 84 7% 5 22 23% 16%
Jacoby Ellsbury 21 142 15% 9 29 31% 16%
Ian Desmond 13 91 14% 8 27 30% 16%
Jose Altuve 38 174 22% 15 42 36% 14%
Yasiel Puig 3 64 5% 3 16 19% 14%
Josh Harrison 10 99 10% 6 26 23% 13%
Alcides Escobar 17 166 10% 10 45 22% 12%
Bryce Harper 6 149 4% 6 41 15% 11%
Xander Bogaerts 10 156 6% 6 38 16% 10%

Maybin is a clear outlier having more than doubled his 16 percent stolen base rate from last season. Of course, that is in just three games since he’s returned from his wrist injury. It is way too early to draw any conclusions, but by all means pick up Maybin if you need to speculate on speed, even in shallow formats.

About half of the list is players like Starling Marte and Jose Altuve who were drafted for speed. The more the merrier. However, there are a few gainers who really weren’t considered major speed threats who could dramatically improve their fantasy stock if they maintain the change. Rougned Odor could be a really sneaky 20-20 threat over a full season, although both his suspension and his abysmal 3.0 percent walk rate will likely hold his stolen base totals below that. Bryce Harper has already started to steal more bases, so Barry Bonds should be pleased. Meanwhile, Xander Bogaerts has not shown the power growth many expected, but his speed growth should be sustainable. He has improved his walk rate from 4.9 percent to 7.4 percent this season, and he has maintained a high BABIP for long enough for me to think it likely reflects skill. I don’t expected 20 steals hitting third in the order, but 15 seems possible.

Less Aggressive Basestealers, 2016
2015 2016
Runner SB Opps SB Rate SB Opps SB Rate Change
Jean Segura 25 116 22% 5 55 9% -13%
Charlie Blackmon 43 163 26% 3 24 13% -13%
Billy Hamilton 57 91 63% 7 14 50% -13%
Delino DeShields 25 103 24% 4 33 12% -12%
Kevin Pillar 25 100 25% 4 28 14% -11%
George Springer 16 102 16% 3 39 8% -8%
Elvis Andrus 25 133 19% 4 36 11% -8%
Lorenzo Cain 28 127 22% 5 31 16% -6%
Christian Yelich 16 141 11% 3 53 6% -5%
Gregory Polanco 27 124 22% 5 30 17% -5%
Melvin Upton Jr. 9 41 22% 7 41 17% -5%

By requiring a minimum of three stolen bases, I somewhat limited this trailerboard, but many interesting names remain. Jean Segura has really not taken advantage of his many opportunities to steal, which have been fueled by his .373 BABIP. He’s a definite sell candidate if your leaguemates think he has another 20 steals to go this season.

George Springer, Christian Yelich, and Gregory Polanco all fit the mold of young, speedy players who could be becoming less aggressive on the basepaths as they gain power. Yelich and Polanco especially are in the midst of power breakouts. Their .525 and .518 respective slugging percentages are up more than 100 points on their career numbers, and Jeff Sullivan detailed Yelich’s declining groundball rate, which should play into his power’s favor. It is too early to have the Mike Trout fear—such that anyone can fear a top-five fantasy player—of rapidly declining stolen base totals, but I wouldn’t expect any of the three players to reach 20 steals anymore.

We hoped you liked reading Stolen Base Opportunities by Scott Spratt!

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Scott Spratt is a fantasy sports writer for FanGraphs and Pro Football Focus. He is a Sloan Sports Conference Research Paper Competition and FSWA award winner. Feel free to ask him questions on Twitter – @Scott_Spratt

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balfazzar
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balfazzar

Springer already has 5 CS on the year. Is he really less aggressive or just less successful?

Jackie T.
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Jackie T.

Right, maybe I’m looking at this wrong, but shouldn’t aggressiveness be measured by SB attempts and not actually successful SBs?

albertkly
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albertkly

Exactly Jackie