How long do your tyres live??

From Sheldon Browns

Skid Patch

Fixed-gear riders who make a habit of doing "skip stops" you will wear the rear tire out considerably faster than those who use a brake. This problem is exacerbated by certain gear ratios, because they may tend to repeatedly skid on the same section of the tire.

Riders who plan to do a lot of skip stops should consider the ratio when selecting their chainring and rear sprocket. The mathematics of this is actually fairly simple:

    * Simplify the gear ratio to the smallest equivalent whole number ratio.
    * The denominator of the resulting fraction is the number of skid patches you will have on your rear tire. 

Examples:

    44/16 simplifies to 11/4, so there would be 4 skid patches.

    45/15 simplifies to 3/1 so there would only be 1 skid patch.

    42/15 simplifies to 14/5, so there would be 5 skid patches.

    43/15 can't be further simplified, so there would be 15 skid patches.

This is based on the assumption that you always skid with the same foot forward.

If you are an ambidextrous skidder, and the calculation gives an even result, your number of skid patches will be the same.

If you are an ambidextrous skidder, and have an odd denominator, the number of possible skid patches will be doubled. 

So given this info from Mr Brown

You want to have as many skid patches as possible, clearly the best way is to have a gog which is a prime number (13, 17, 19) or a prime number chainring (harder to find). If you have a low number of skid patches. Every so often loosen your rear wheel and move the chain round your cog a few teeth there by moving the skid patches to a new part of the tyre.