How MLB’s top stealers are using the new regulations against pitchers

The two biggest base stealers in MLB thus far have been Ronald Acua Jr. and Esteury Ruiz.

After almost two months of play, it is reasonable to say that Major League Baseball has been successful at rewarding basestealers. What would be a new record in year-over-year stolen-base advances was achieved as a result of new rules expanding the bases and limiting the number of times a pitcher can disengage during a plate appearance — twice, though pitchers are allowed a third pickoff attempt that they must succeed on. In other words, there have already been 13 players who have successfully stolen 10 or more bases; for comparison, 24 players successfully stole 12 or more bases throughout the entire 2014 season.

The stolen base is back in style, so we thought it would be a good idea to look at how the current stolen base leaders, veteran outfielder Ronald Acua Jr. of the Atlanta Braves and rookie outfielder Esteury Ruiz of the Oakland Athletics in the American and National Leagues, respectively, are going about their larceny. We also wanted to see if either of them could attribute their success to the new rules for their early-season success. (Please keep in mind that the data is as of Saturday AM.)

Let’s get started.

Esteury Ruiz

Ruiz was the important player that the Athletics acquired in the Sean Murphy trade last winter. Despite the fact that the business had doubts about his offensive potential because of his reliance on pitch contact, there was no denying that he was a fun player to watch. He is tremendously quick, and he uses that speed to his advantage in the field and, more significantly in this situation, on the basepaths.

Ruiz had 18 steals on 21 attempts as of Monday, which put him in first place in the majors. It’s worth categorizing him as an aggressive thief given that he’s only had slightly more than 50 opportunities to steal bases, which Baseball Reference defines as occasions on first or second base with the next base available. Three multi-steal performances, including a four-steal performance on April 26 against the Los Angeles Angels, have increased Ruiz’s total number of stolen bases.

Ruiz consistently performs well (tied for eighth) in pickoff throws drawn. Since some pitchers won’t feel comfortable boxing themselves in by throwing over twice, others questioned how baserunners would use the new disengagement rules against pitchers. While watching at least one throw, Ruiz has stolen nine bases, two of which were after watching two throws. He has left the table on three of the four instances when he has drawn two throws, indicating that he approves of the new regulations.

Ruiz would complete the season with 64 stolen bases, the most by an Athletics player since Rickey Henderson swiped 66 bases in 1998, if he maintained his current pace over 150 games. In addition, if Ruiz manages to steal 67 bases, he will break Kenny Lofton’s AL rookie single-season thefts record.

The outcome of Ruiz will ultimately depend on his ability to board, at the risk of stating the obvious. He was hitting when Monday began.270/.331/.362, but nine hit-by-pitch outs (instead of six walks) increased his on-base percentage. We will note that Ruiz was hit by 27 pitches in the minors last season, indicating that his propensity to get hit by pitches in the lead arm or elbow is a consistent attribute and not a small-sample aberration.

Ronald Acuña Jr.

Large totals of stolen bases are nothing new for Acua. He almost achieved a 40-40 effort this year, and in roughly 80 fewer games than last season, he has already achieved more than half of his goal of 29 (17 on 19 tries). In 150 games, he should steal 64 times. For what it’s worth, the Braves haven’t had a player with more than 50 thefts since Otis Nixon had 72 in 1991.

It shouldn’t come as a surprise that pitchers are quite interested in Acua as well. He had 35 pickoff throws drawn as of the weekend, which was the most in the majors. That comprises eight circumstances in which he attracted two pickoff throws.

Acua hasn’t been nearly as aggressive when pushing pitchers to the limit as Ruiz has. Only one of his steals—his first of the year—came after a pair of throws. (Left-handed pitcher Patrick Corbin of the Washington Nationals had Acua leaning on his first pitch, but they were unable to record the out. Prior to Acua stealing second, Corbin threw over once more.) Acua’s sweet spot for stolen bases has always been after the first pitch, whether by happenstance or intent. More over half of his steals—eight—have come from that circumstance.

Acua, on the other hand, has attempted less stolen base attempts despite having far more possibilities than Ruiz. We believe there are a few clear explanations for this rate differential, including the fact that the Braves are more likely to hit a home run, making the extra base meaningless, and the fact that the A’s are generally more active on the basepaths. Whatever the situation, Acua is undoubtedly still collecting his fair share of steals and has a chance to attempt his second career 30-30 season.