Compare and contrast USPSA and IDPA scoring

[Bill Nesbitt]

bowling pints,

Sounds like a fun game. See who falls down first???

[Matt Griffin]

I think an easier way to state it is that IDPA tends to have more complicated, lower round-count stages, a setup which rewards accuracy over speed in BOTH sports. Although not terribly common, when you have a heavy movement course in USPSA but only 50 or 60 points available, then accuracy is rewarded much more than speed. Another way to say it is that IDPA courses tend to be low hit factor courses, and should be shot appropriately.

H.

[RickB]

We had a "non-denominational" single stack match at our range, because there's both an IDPA club and a USPSA club in residence, and I wanted to attract as many shooters as possible. I modified Vickers scoring, so that major was worth .3 second per point, and minor .5 second per point, and had everyone, regardless of whether they were classified in USPSA Single Stack, or IDPA ESP or CDP, shoot in a single division for overall standings. There was some headscratching, but nobody complained. Afterwards, I explained it this way:

USPSA's hit-factor scoring is essentially points-per-second. The target has the same points value for each scoring zone as IDPA, and the shooter must discover the best ratio of time to points, to get the best score. The shooter must do the same in IDPA, but the penalty for each point dropped is so much greater, that the shooter is generally compelled to shoot somewhat slower/more-accurately in order to attain the best score.

Here's an example: The El Presidente is shot in both IDPA and USPSA, and while they differ a bit, everyone knows the El Prez. Using hit-factor scoring, two shooters might post scores like this:

T1: Four Alphas (down zero), T2: Two Alphas, two Charlies (down two), and T3: Three Alphas, one Delta (down three), in a time of five seconds flat.

Score: 55 points in five seconds = hit factor of 11.0.

Shooter two gets all Alphas (down zero) on all targets, in six seconds.

Score: 60 points in six seconds = hit factor of 10.0

Shooter one wins.

Using Vickers scoring, shooter one's score is 7.5 seconds, while shooter two's score is 6.0 seconds; shooter two wins, and by a much larger margin.

Using the scoring system in place for Sunday's match, shooter one would have a score of 6.5 seconds, while shooter two would still have a score of 6.0. Shooter two wins again, but the margin is smaller, as the scoring system tips the balance back toward speed.

So, which is more important in the "real world", speed or accuracy? Both USPSA/IPSC and IDPA subscribe to the theory of "DVC": Speed, Power and Accuracy as the three equally-important legs of a tripod. Which scoing system strikes the best balance?

Edited September 9, 2008 by RickB

[JKSNIPER]

So lemme get this straight....hit factor is a product of consulting the tide tables, while figuring in the phase of the moon, counting points taken off your S.A.T., times the power factor, divided by the age of Flex.

Not too complex.

Glad you straightened it out for me Flex.

I can now die happy.

JK

[Flexmoney]

Windage and elevation... If you can dope, your way ahead of me and figuring hf.

Hit Factor is points per second.

[shred]

The cool thing with hit-factor scoring is different stages have different equivalent time penalties for poor shots. Different shooters even have different equivalent time penalties for poor shots-- the slower you shoot, the more accurate you have to be. The downside is it sucks to explain or figure out without a computer.