this is a case where using conventional methods (i.e. actually watching) rather than stats probably wins. that or just using simple logic, of course. I'll just repeat some of that simple logic then: but you don't know why those errors occurred. you cant just look at raw data like that and make that conclusion. other than going back and looking at every error, it's impossible to tell why the error was committed. and thus impossible to say that pierre's speed doesn't have an effect on the defender. which is why i just suggested that fundamental logic (crazy, i know) might be a better way of coming to a conclusion here. that fundamental logic of course being, when a defender knows he has 4 seconds until the batter reaches first base versus three seconds, he'll react accordingly. You're missing the point. Regardless of why or how the error took place, he's not causing a higher rate of errors than a hitter with less speed. you don't know that. for all you know, all 56 of the times that pierre reached on an error could've been caused by his speed. obviously at the same time, none of the 56 could have been caused by his speed. point is, we just don't know. so when you look at stats to determine if his speed has an effect, and the stats don't give you a clear answer... and i know this board is absurdly stat-heavy (vs. scouting)... but don't you think it's time to just stop and think for a moment about the logical answer? Take a look at the numbers posted earlier: Juan Pierre ground balls: Reached on error 56 times out of 2503 possibilites. Aramis Ramirez ground balls: Reached on error 49 times out of 1548 chances. Juan Pierre reached on an error in 2.2% of the chances he could have reached on an error. Ramirez reached on an error 3.2% of the time he could have reached on an error. In other words, a much slower runner reached on an error more frequently than Pierre. Whether all 56 times were caused by Pierre's speed, questionable scoring by the official scorer, night blindness by the fielder, or simply God's will, he's still not reaching on an error as often as a slower runner. Therefore, what good is it that his speed is causing throws to be rushed when it's not causing him to reach base more often than a slower runner?