Now Pinch Hitting for Oakland...

What you might not know is that the A's of that era employed another quite-strange method of roster management, most notably in September of 1972 as they tried to hold off the White Sox for the division title...(Charlie) Finley and manager Dick Williams concoted a bizarre plan: the A's numerous second basemen, none of whom could hit, wouldn't be allowed to hit. Instead every time the second baseman came up, Williams would send up a pinch hitter...
-Rob Neyer, Rob Neyer's Big Book of Baseball Lineups (New York: Fireside Books, 2003) 170.

Late in the 1974 season, Dick Williams decided that he had no second basemen, but lots of pinch hitters, so he began rotating five second basemen, pinch hitting whenever one of them came to bat.
-Bill James, The New Bill James Historical Baseball Abstract (New York: Free Press, 2001) 516.

Did the A's really do this? If so, did they do it in multiple seasons, or is either Neyer or his mentor James mistaken? If they did do it, was it effective?

On September 1, 1972, the A's were leading the AL West Division over the second-place White Sox by 1.5 games, having moved back into first place two days before after spending five days in second place. Oakland was getting almost nothing at the bat from its second basemen: Tim Cullen was hitting .250, Ted Kubiak was at .199, and Dick Green, who had played very little due to a back injury, was hitting .267. On August 30, they traded a minor leaguer to the Cardinals for Dal Maxvill, a defensive specialist whose lifetime average, at the time, was .220. This is the event that Neyer mentions as marking the beginning of the A's experiment.

An examination of the box score shows that Neyer's account is not strictly correct. From September 1 through September 28, A's second basemen came to the plate 59 times and were pinch hit for 44 times. However, during the period from September 17 to September 28, second basemen came to the plate 15 times and were pinch hit for 23 times, so it seems that if Williams was using this strategy, he may have been using it consistently for only a relatively short period, and he was never as strict about it as Neyer implies. There was only one game in which the second basemen had no plate appearances and were pinch hit for every time up. After the 28th, the strategy was abandoned as the division had already been clinched.

The strategy was generally effective. From the 1st to the 28th, the pinch hitters hit .237 with a .326 on-base percentage and they, and their pinch runners, scored 5 runs. The second basemen hit .214 with a .237 OBP and scored 4 runs. Ironically, during the 11 days in which the strategy was employed most strictly, the second basemen out-hit the pinch hitters .286 to .158. The A's did win; they went 17-9 from September 1 to September 28, including 7-3 from the 17th to the 28th, and gained 4.5 games in the standings.

How about 1974? James is wrong about at least one thing: Alvin Dark was the A's manager in '74, not Dick Williams. If Dark did use this strategy, he must have done it only for a very short time. During the entire month of September, A's second basemen (who almost always batted ninth) had 82 plate appearences to their pinch hitters' 21. However, from September 15 through September 20, second basemen came up to the plate 9 times, and were replaced by pinch hitters on 10 occasions, so it's possible Dark used this strategy for about a week. In any case, it didn't work. During the entire month, the pinch hitters for A's second basemen batted .053 (1 for 19) with 2 walks. Second basemen themselves batted .122 with 5 walks.