Austin Slater drew a leadoff walk in the first inning. And the game was afoot.

Padres left-hander Blake Snell threw a pickoff attempt to first base. Slater raced back. Another pickoff throw. Another retreat. A third time. It wasn’t a charm.

When Snell finally delivered a pitch to the plate, Slater had him so thoroughly read to render him dog-eared. Slater dashed for second base, and between his ample jump and the loopy, 77-mph breaking ball, the Padres had no chance.

It was the 22nd stolen base in Slater’s career. It came in his 23rd attempt. It didn’t turn out to be a difference-making play and it didn’t lead to a run in the Giants’ 5-4 victory last Friday at Oracle Park. But it was the essence of modern basestealing in the major leagues — a blend of art and instinct backed by an ever-increasing haul of data-driven science, all designed to maximize the reward and minimize the risk.

It’s working. In the seven decades for which data is more or less complete, major-league basestealers were never more efficient than they were in last year’s pandemic-shortened season. They were successful on 75.2 percent of attempts. And now that record is being left in the dust. Base stealers are even more successful this season. Through Wednesday’s games, the major-league success rate was an all-time high of 76.9 percent.

That might not seem like a major jump, no pun intended. It might seem like a ho-hum continuation of a decades-long trend as teams have quantified the potential penalty of making an out versus the relative gain of advancing an extra 90 feet. The single-season stolen base success rate ranged from 59-65 percent in the 1960s, from 62-68 percent in the 1970s, from 65-70 percent in the 1980s, from 66-71 percent in the 1990s and from 68-74 percent over the first 19 seasons of the 2000s.