Blasters have the lowest tracking of all guns. (Lasers the best). This is a vague question but I can give some insights...

Railguns, you better not be moving to get the most out of your tracking, and you would be snipe in this case.

If you are runnin blasters, here are a few things, and what to use to compensate.

• The bigger the ship, the lower tracking needed. (Target Painter)
• The slower the target, the lower tracking needed. (Webbers)
• The slower your ship, the lower tracking needed. (Lower your speed.)

Other than this, it really depends on what you will be flying. If you have a BlasterMega, for instance, you'll want anything cruiser and smaller webbed to get good hits, and web the bs's and bc's to get more perfect shots in.

the way tracking is now a days, you'll want to squeek in something for tracking if your gang dps is tight. so instead of 3xDMG mods, go 2xDMG and 1xTracking. You will think your dmg multiplier is lower, but your tracking boost will make up for it whit better shots.

RedMage gave a good answer.

This is a real "how long is a piece of string" question. The closer an object is orbiting you the more tracking you need and the same with speed although with that you must also figure in your own speed and trajectory.

In my experience a value of 0.06 is quite typical for a Blaster BS but as RedMage pointed out blasters do track slowly and large turrets track slowly so with large blasters you will really suffer. As pointed out Webbers are your key here.

The other problem is that tracking enhancers and computers increase your tracking by a percentage so have a much greater effect on turrets that already track well. A scripted Tracking Computer II will give you a decent 30% boost but on 0.0604 that only brings it up to 0.07852. Clearly better but not hugely.

The best way of testing it is get your corp mates to fit buffer shield tanks on various classes of ships, eg. frigates, cruisers, battlecruisers, with abs and/or mwds, and have them orbit you at various distances and speeds while you shoot at them.

There are various combat log analysis tools that will tell you how often you hit and the "grade" of hit, eg. barely scratches, hits, excellent hit etc.

There is also a tool that ably demonstrates in a nice graphical way the affect of all these factors. I will try to find it and add a link although if memory serves it is on the eve site which I can't access at work so it may not appear till later.