One aspect of the 2017 Yankees that is, at least to my eyes, relatively unheralded is how well-rounded they were. Understandably, their power-packed lineup and monstrous bullpen conglomerate received most of the media attention. The Yankees also boasted a top-10 rotation in MLB by fWAR, just a hair behind the Astros' starting corps. Their only weakness was their defense, and even in that area they were more subpar than outright awful.
What truly took me by surprise, though, was their baserunning statistics. FanGraphs carries a stat called BsR, which converts a given player's baserunning performance (stolen bases, advancing on hits/sacrifices, avoiding double plays) into runs above (or below) average. These are the 2017 rankings for team BsR:
The Yankees ranked in 5th place with 10.6 baserunning runs above average, just ahead of Cleveland's 9.9 mark. If you had asked me which of the two teams was better on the bases before I looked up the numbers, I would have put money on Cleveland. Thank goodness you didn't, and thank goodness time travel doesn't exist - or does it?.
Who were the main culprits? Unsurprisingly, they were Brett Gardner and Jacoby Ellsbury, who combined for over 10 runs above average all by themselves. Didi Gregorius and Aaron Hicks were no slouches either, posting marks of 3.3 and 2.5, respectively. These four players are all known for their speed, so it makes intuitive sense that the numbers like them.
It would be unfair to the rest of the Yankees, however, to ignore their performances completely. For while no other Yankee posted a BsR of over 2.0, there were none who were outright awful. Of the players who accrued at least 300 plate appearances for the Yankees in 2017, only Matt Holliday posted a BsR under two runs below average. The next worst baserunner was Gary Sanchez, who managed a below average but totally acceptable -1.4 mark. Every other Yankees starter was either average or above it. Thus, the 2017 Yankees' baserunning prowess wasn't driven by a handful of players; rather, it was a team effort.
In my opinion, the Yankees' avoidance of awful baserunning is the result of their relatively conservative team-wide approach on the basepaths. When stealing bases, the Yankees are extremely smart about picking their spots. This is borne out by their extremely low caught stealing totals (22, third-fewest in MLB in 2017) relative to their stolen base total (90, 12th-most in MLB). In fact, no other team that stole more than 90 bases was caught stealing fewer than 28 times. It's safe to say that when a Yankee decides to steal or gets a green light from the bench, either he or the coaches are pretty sure about their chances.
This conservative, risk-averse approach extends to more general baserunning decisions too. Watching the 2017 Yankees, I was often surprised by how safe they played it on the bases, especially when someone got a hit with a runner on second. Maybe I'm haunted by memories of Rob Thomson doing his best impression of a Dutch windmill at third base, but last year it seemed like Yankees baserunners were held at third way more often than most.
This conservative approach to baserunning is perhaps less exciting and more frustrating than a more aggressive stance, but by the numbers it works best. In general, the gains a team makes by taking a successful baserunning risk is far less than the losses from a gamble gone wrong. This is because by advancing a base you're only increasing your potential to score (unless you're stealing home), while by being TOOTBLAN-ed you're costing your team not only a runner but also an out. By being safe and taking fewer risks, the Yankees are treating their outs carefully, which every smart team should do. And let's face it, when your middle of the order goes Judge-Stanton-Sanchez-Bird, all runners have to do is stay on base until someone dingers you home.
Barring extreme circumstances — like the infield dirt of YSIII being replaced by quicksand in a desperate attempt by Rob Manfred to increase viewership — the Yankees should continue to be a good baserunning team in 2018. Aaron Boone seems like a guy who is reasonably open to sabermetric principles, and the departure of Holliday should be considered addition by subtraction in terms of net baserunning runs. Compared to their other, more obvious strengths, the 2018 Yankees' baserunning probably won't get much attention. In a tight division race where every run counts, though, the Yankees' prowess on the basepaths is sure to come in handy.