The Giants' June Swoon

Monday morning, June 9, the San Francisco Giants had a 42-21 record, which was the best not only in the National League West but in all of baseball. Since then, they've gone 5-16, the worst record in all of baseball. But hey they're still in first place, half a game ahead of the Dodgers, so all's well, right?

Maybe not. Since moving to San Francisco in 1958, the Giants have had 13 seasons before this year in which they had a 5-16 record over 21 games. (Thanks, Baseball-Reference Play Index!) Here's how they fared in each of those years:
1972: 69-86, fifth of six in division
1974: 72-90, fifth of six in division
1976: 74-88, fourth of six in division
1979: 71-91, fourth of six in division
1980: 75-86, fifth of six in division
1985: 62-100, sixth of six in division
1991: 75-87, fourth of six in division
1992: 72-90, fifth of six in division
1994: 55-60, second of four in division
1996: 68-94, fourth of four in division
2006: 76-85, third of five in division
2007: 71-91, fifth of five in division
2013: 76-86, third of five in division

A couple observations: First, from 1958 to 1971, a span of 14 seasons, the Giants never were as bad as 5-16 over 21 games. In each of those years, their regular center fielder was Willie Mays. Mays was traded in 1972.

Second, and more ominously, the Giants not only have never won their division during a year in which they've gone 5-16, they've never even had a winning record in those seasons. 

Can the Giants shake off their slump and hold off the Dodgers? History says they won't. (Unless they bring back Willie Mays.)