Originally Posted by operator

Sheldon brown does not recommend a tight chain. He recommends a chain that is PROPERLY tensioned. Which means not tight enough so that it binds/laser tight in one spot but not so loose that the chain is dropped on a bump.

Variations in cog/chainring/cranksets all produced different results. Some combos have huge variation as the chain goes around, some not as much. This will affect how easy it is to get the proper chain tension.

Chains on ss/fg bikes should ALWAYS have some play in them. Run them laser tight and watch as your drivetrain grinds and self destruct in no time. Having said that you basically have two options of doing it

1) Run the chain tight then progressively move the axle forward until there are no spots that bind
2) Run the chain loose and progressively move the axle backwards until it binds, then move it a tad forward again

Park says 1/2" up/down which is fairly acceptable. You should not be able to push the chain off the cog/chainring by hand if the tension is correct. This will always give you the lower limit on chain tension.