The first defensive shift was in the late 1850s. In the earliest days of baseball, the shortstop was a fourth outfielder. Remember: the game was entirely different. Left and right fielders played much closer to the foul lines, because of fair/foul hits. Much, MUCH closer. They also played much shallower. In the earliest days, a putout could be recorded if caught after one bounce. So you have to visualize where the outfielders were stationed before the ball was hit. The left and right fielders hugging the foul lines, and two centerfielders (the shortstop and centerfielder). The three infielders were stationed not too far away from their respective bases. And the pitcher, he was a much more active fielder back then. He more or less lobbed the ball up there for the hitter to punch thru the holes, so it was the pitcher’s responsibility to be involved with the defense (think of a slo-pitch softball pitcher who after tossing the ball, usually starts to back up after the ball leaves his hand). Hopefully you can visualize where the defense was playing; it’s so foreign to how we see them set up today.
Anyway, what with the 4 outfielders playing in, balls often did go over their heads. It was the shortstop’s responsibility to be the cutoff man.
Dickey Pearce changed all that. He noticed that he could get more putouts and assists by playing where the shortstop sets up now. It also enabled the second baseman to play on the first base side of second, where as before he was often “require” to get ground balls up the middle on either side of the bag. And the 2nd baseman could also make more plays.
THIS was the first defensive shift to combat infield grounders that some players were adept at hitting. There are players today (Jeter with all his GO6) who would have been like Willie Keeler, hitting ’em where they ain’t, back in the 1850s.
I can imagine that the Atlantic members, after losing to the Eckfords, sitting around trying to figure out how to stop all those ground balls that were getting past Charlie Smith, John Oliver and Mattie O’Brien. Pearce (or somebody) suggests that Pearce move in, Oliver slides over a little towards first, and see if we can’t stop those darn (or the appropriate 1850s version or darn) Grum brothers (or whoever it was) from getting all those pesky little hits. THIS was the first shift to combat a specific hitter’s batting style. I/we just haven’t a clue 150 years later who that batter was.