Experiments to try with the
Baseball HR Simulator

See a separate page (opens in this same window) for information about this program and its use.

Explore the effect of changing bats in college baseball:

Starting in the 1999 season, the NCAA has phased in some changes in the performance of metal bats used in college baseball. These take full effect in the 2000 season. I have a collection of reports on this subject if you are unfamiliar with this situation. These new rules require that a batted ball not exceed 97 mph when a ball pitched at 70 (+/- 2) mph is hit by a bat swung at 66 (+/- 1) mph as measured 6 inches from the end. Other details are in the NCAA testing protocol.

Notice that a high fly ball was a home run with those older bats under conditions where the 1999 bat produced a double, while the 2000 bat leads to a fly-out at the warning track.

Additional experiments:

Try one of those speeds, say 97 mph, at the original angle of 44 degrees and then explore what happens when you vary the angle of the hit ball. You will find that the optimum angle is around 35 degrees and that this easily produces a home run. Note that this means the new bats will not eliminate homers, or even eliminate homers on poorly hit balls, but it will increase the importance of a good swing for power hitters.

Estimate speed for some hit. Note that both angle and speed affect where the ball goes, so knowing only one point (say where the ball landed or that it hit a fence at a certain spot) is not enough to define the speed. You need some second piece of information, such as how high the ball went at the peak of its flight or where that peak occured to narrow down the range of possibilities. (Determining the speed and angle is a necessary step when doing what is described in the next paragraph.)

Estimate the range for a ball that hits some fixed object. That application was the original motivation for writing the Fortran program used to analyze J.D. Drew's monster 550' home run back in February 1997, the program later converted to Java with the addition of a graphical display and more options. Some of the features in Omaha's Rosenblatt Stadium are there to facilitate this for the College World Series.

Compare long hits in different ball parks. It is easy to set up a particular hit and then choose a different fence location to see whether some other park (or direction in the same park) would hold it. The list of fence options is long enough to span most possibilities, but I will gladly add a few more on request. [At some point I could add a parameter so a user could choose a completely different set of fence options or make one user-defined.]

Also note that experiments with average hitters in a batting cage have shown batted balls in the 60 to 80 mph range. Not everyone is a power hitter, and you can also use this program to look at what it takes to get a hit over the infield and short of the outfielders when the ball is not hit so hard.

Range of possible ball speeds

A naive calculation assuming that the maximum speed of a batted ball will really be only 97 mph with the "Y2K" bats in college baseball would lead you to think that no home runs will be possible with these bats in some ball parks. This is not the case.

The NCAA reports on lowering the speed of batted balls have implied that the older bats only hit the ball at a max speed of 113 mph, but we know that J.D. Drew hit a shot consistent with the ball leaving his bat at 135 mph. NCAA press releases rarely say they used a nominal pitch and bat speed for those tests, or that the speeds used have varied from test to test, and newspaper reports usually omit such caveats even when provided. Power hitters should still get ball speeds in the 110 to 120 mph range with the new bats.

As a guide, I have produced a simple table that linearly extrapolates my estimate of what the tests indicate for a batted ball under the nominal test conditions used by the NCAA to cases with both lower and higher bat (and/or pitch) speeds. You should not assume that the following represents anything more than a wild guess of how different bats would really perform under extreme cases that were never tested in the lab.

Table of estimated change in batted ball speeds with change in bats.

1998 1999 2000 initial
88 mph 85 mph 82 mph 79 mph
104 mph 100 mph 97 mph 93 mph
115 mph 110 mph 106 mph 102 mph
130 mph 125 mph 121 mph 116 mph

Some reminders about the program: