And here's why USPSA favors speed a bit more.

Say there are two shooters in a given division. There are 8 targets with 2 hits each

Shooter 1: 10 seconds, 16 A's (down 0 in IDPA)

Shooter 2: 8 seconds, 9 A's and 7 C's (down 7 in IDPA or 3.5 seconds penalty)

IDPA:

Shooter 1: 10 seconds total time (stage win)

Shooter 2: 11.5 seconds total time

* Shooter 1 wins by a healthy 1.5 seconds

USPSA:

Shooter 1: hit factor of 8 (80 points for the 16 A's, divided by time of 10 seconds)

Shooter 2: hit factor of 8.25 (66 points for the 9 A's and 7 C's, divided by time of 8 seconds) (stage win)

* Shooter 2 wins by a narrow margin

If Shooter 2 is shooting major, they get more points for their C shots.

Shooter 2 major: 9.125 (73 points for the 9 A's and 7 C's, divided by time of 8 seconds)

* Shooter 2 wins by a large margin

So not only does shooting faster help you win, but shooting a larger caliber gives you more points for imperfect shots.

To complicate it even more, points are awarded on a stage on a curve. The shooter with the highest hit factor gets 100% of the points available for the stage. So in the case of Shooter 2 shooting a .45, they are awarded 80 points (16 shots * 5 points).

Shooter 1 is awarded 87.67% of the points available on the stage. This is calculated by dividing their hit factor by the winning hit factor (8 / 9.125). This gives shooter 1 70.136 points for the stage.

Repeat this process for every stage and add up all the points. The shooter with the most points wins. Note that all of these calculations include only shooters in the *same* division. So the calculations only take shooters you compete with into account. To perform overall scoring, do the exact same process above but use all shooters. This is why you'll see a different number of awarded points based on whether you are looking at your division or the overall scoring - your scoring is always relative to the people you're being compared to.

I ignored penalties in the process above. Any penalties you receive is subtracted from your total points before the hit factor is calculated. It is possible to end up with 0 points after penalties are removed. You would be awarded 0 points for a stage in that case.

A procedural penalty is 10 points (frequently 10 points per shot while you were doing the infraction - like shooting outside the fault lines)

A no-shoot is 10 points

A miss is not only the lack of gaining points for the hit, but you also subtract 5 points. So compared to someone who had an A hit (+5) and you had a miss (-5), you lose 10 points.

So in short, the scoring is much more complicated. The only thing you can really do while shooting is calculate your hit factor and compare that to other shooters.