Seven or eight years ago, as I neared the end of my adult amateur baseball career, for the first time in my life I found myself playing a lot of outfield. I didn't feel very confident, and after thirty five years of playing third base (when not pitching) I was also pretty bored. So I got into the habit of counting the strides either I or another outfielder would take to the ball on our way to catch it.
I soon learned that this was a relatively quick and dirty way to gauge range and now do it by habit. The average running stride is about the same as the height of the runner (1.14 feet in track and field) - so let's assume six feet. To test the accuracy of that assumption, a player stealing second generally takes 12 strides. Taking into account the lead, the start, and the takeoff point for the slide, those twelve strides cover about 70 feet, so I think the calculation is roughly correct.
I used to feel pretty good about myself if I managed to reach a ball after running 15 strides or so - around ninety feet (obviously, if the ball hangs in the air, is hit on a line, or the outfielder gets a late "jump" this affects the number of strides and one's ability to "get under it," but over time I've still found it to be a useful tool).
If you get the chance to watch a major league outfielder on a regular basis you'll discover that very, very few have a range of less than fifteen strides, or ninety feet. Most get up to eighteen or nineteen strides, say 110 feet or so. Above twenty strides - 120 feet - is relatively rare, and twenty-five strides, or 150 feet, is incredibly uncommon and seems to be the upper limit. Torii Hunter used to approach twenty-five, and so do guys like Jacoby Ellsbury.
Using the same method you can also determine just how deep an outfielder is playing, which otherwise is pure speculation. I've seen a few major league centerfielders in parks that are 410 feet to dead center turn and run twenty strides before pulling up at the warning track while chasing balls hit over their heads. That player is setting up only about 280 feet from home - very shallow in today's game. But there are others who can barely get ten strides in, meaning they set up 330 or 340 feet from home. Similarly, you can use the same method to determine how far corner outfielders are playing from the line.
I'm curious - does anyone else count strides this way? I find it interesting is that the range of most outfielders in any direction is about ninety feet, the same as the distance between the bases.
I like that.