Wednesday, September 9, 2009

Bowling Handicaps

Handicapping systems are nice things. They allow people lacking skill (like us) to compete with people with a lot of skill (like most of the rest of the league). This way, you can get greater participation in bowling leagues, and everybody feels like they have a chance to win. Handicaps level the playing field, but usually only partly. There is no standard handicapping system in bowling. In our league, we have a 90% handicap standardized to a score of 220. It only applies if your average is less than 220. If your average is greater, you have a zero handicap. It is calculated this way:

Handicap = (220 - average) x 0.9

After you've done the calculation, just remove anything after the decimal. Notice that there are two parts to the calculation. There's the 220 part. We'll call that the constant. Then, there's the 0.9 part. That will be the percentage. For those of you who used to run out of math class crying, 0.9 is the same thing as 90%. Different leagues use different constants and percentages. But how do they affect your chances of winning as an individual or team?

What inspired this post was something that happened at our pre-league meeting last week. It was decided to change our handicaps for next year. One bowler in the league (not on our team) last year finished the season with an average over 220, a 223. So, it was proposed that we change the constant to a 225. At this point, John and Joe looked at me and asked, "How does that affect us?" I must admit embarrassingly that I had no idea.

So, here's the skinny on handicaps. I've already written about some of this, but here's a bit more. The constant part is largely irrelevant. It turns out that the new handicap will have no effect on our chances of winning. It's really the 0.9 part that matters. Here's an example. One bowler has a 100 average, another a 200 average. Using the equation above, these equate to handicaps of 108 and 18, respectively. If each bowler bowled their average game, they would get scores of 208 and 218. So, the the better bowler has a 10 pin advantage. If the constant is changed to a 225, does this advantage change? Here are the numbers: Bowler 1: Avg=100, Hcap=112, Avg Hcap Game=212; Bowler 1: Avg=100, Hcap=22, Avg Hcap Game=222. Notice, there is still a 10 pin advantage. So, the constant is largely irrelevant to your chances of winning.

It only affects those bowlers who have VERY high averages, averages exceeding that constant. Here's why. Imagine if the constant was 100 meaning that anyone with an average over 100 has a zero handicap. This would help no one, except people with sub 100 averages. In this case, our team would not stand a chance against most other teams because we would all have zero handicaps. This is why the constant is always set above the highest average anticipated for the league.

What if you can't anticipate the highest league average? One way to avoid this problem would be to set the constant to 300. I'm not sure why this isn't done, but my hunch is that it is to make handicapped game scores exceeding 300 pins a rare thing. Do you want to see someone bowl a 400 in a single game? It just bothers you, doesn't it? It would be like snow in July, something that occasionally curses us in Laramie. If a constant of 300 was used, this would happen fairly regularly. In our 252 games on record, the highest handicapped game is a 284. Without the handicap, it was a 225 by Johnebob. With Johnny's current handicap, he could get a score over 300, but he'd have to roll a 242 to do it, not an easy thing to do for a guy with a 154 average. By using a constant which includes everybody but is as low as possible, you can level the playing field without producing artificially high scores.

The percentage is what really matters in the handicap calculation. If a 100% handicap is used, all bowlers compete equally. As the percentage gets smaller, the advantage to better bowlers increases. The graph below shows relationship between percentage and the advantage a 200 average bowler has over a 100 average bowler using a 220 constant.

If you are a good bowler, no doubt you will be in favor of using a smaller percentage to calculate the handicap. If you are not so good, you will want it to be closer to 100%. When a percentage close to 100% is used, like 90% in our league, it is attempting to optimize two factors: 1) It allows people with less skill to still compete. 2)It gives skilled bowlers a slight advantage, essentially a reward for being better.


  1. As a higher average bowler, I still like the ideo of handicap. It levels the playing field a little bit and definitely helps get a bigger turnout for tournaments and leagues. It brings people to bowl that normally wouldn't because they don't feel like they have a chance to compete. Handicap still leaves an advantage to the higher average (better) bowlers, because it doesn't make up for 100% of the difference. It gives the lower average bowlers a chance, without hurting he higher average bowlers too much.

  2. That's good to hear because if we didn't have a handicapped league, our team could never compete.


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