Mariners revamp baserunning strategies

Club set to take aggressive approach backed by analytics

March 1st, 2021

PEORIA, Ariz. -- One way the Mariners believe they can better exploit their talent this season is on the basepaths, and they immediately began game planning such strategies with position players reporting to Spring Training last week.

Specifically, Seattle’s analytics department presented a video-slide presentation to players on Thursday outlining what the club hopes to accomplish. The Mariners believe they have the personnel capable of being more aggressive on the basepaths, and now they want to supplement that talent with more thorough information and strategy.

“There’s some low-hanging fruit that [shows] we can get better as a team,” Mariners manager Scott Servais said.

In the scope of smaller sample sizes, the Mariners were already well on their way to improving in this area in 2020. Data from Baseball-Reference shows that when they could take an extra base, they did so 50 percent of the time, the fourth-highest rate in MLB. FanGraphs’ baserunning data -- an all-encompassing metric that turns stolen bases, caught stealings, and other plays, such as taking extra bases, being thrown out on the bases, etc., into runs above and below average -- showed that the Mariners were the second-best team on the basepaths. On the more simple side, the Mariners ranked fifth with 115 stolen bases.

But Seattle ranked league average (31 percent) in run-scoring percentage, the rate at which a baserunner eventually scores.

“There's so much more that goes into it, so we've spent a bunch of time here, early in camp, really stressing that we got guys that can run, we got guys that move really well on the bases that we need to be even better than we were last year,” Servais said.

The root of the Mariners’ concept isn’t novel -- more runs equate to more positive results. And with an offense that ranked in the lower tier last year, Seattle is simply trying to get more creative when it comes to run manufacturing.

The Mariners went 24-8 when scoring at least four runs last season and 3-25 when scoring three runs or fewer. Servais has pointed this out multiple times dating back to last season. Collectively, the Mariners hit .226/.309/.370 and were worth 91 weighted runs created plus, a park- and era-neutral metric, where 100 is league average.

“The biggest impact you can have on the bases is when you can pick up two bases when you can go first to third or when you're scoring from second on a base hit, or you can score from first on a double,” Servais said. “That's what really bumps you up as far as the numbers and the metrics baserunning-wise.

“And because you're impacting your ability to score runs, stolen bases are great, they're fun. But when you take a big look at the whole picture here, your biggest impact is your ability to go first and third. So, it's a mindset when you get on first base.”

The offense should improve in 2021, particularly with its top ’19 performer, Tom Murphy, and ’18 All-Star returning from injuries that kept them sidelined all of last season. But that still won’t prevent them from being proactive about finding more creative ways to score.

“We're talking about it a lot during the spring, how important baserunning is, and the percentages of scoring runs when you take the extra base,” second baseman said. “And when we were able to do these kinds of things with an athletic ballclub, I think it'll be imperative this year for us in need in regards to scoring runs and winning ballgames.”