You will know if you shank one of those balls. You will also be able to tell if you slice and hook it. It will turn a little. Think about the distance you can hit one of them...maybe 20 yards with a driver, 10 with a 7i. If you miss your target 2 yards to the left or right with the driver, then you are 10% off line. If that was a 250 yd drive, then you are 25 yards off line. It is that easy. Take out your tape measure ocassionally and take a look at your results, then don't worry too much about it.

They are really used for simple swings. Don't get too carried away from analysis of these littel wiffle things. They are too affected by the wind. Hard to guess what they will end up doing. I use them only for fun drinking games with friends. Hit one back and forth to each other with the same club and the one closest to your feet wins the hole....etc.

You should only be practicing with real balls. If you only have 20 yards in your back yard, only hit 15 yard chips. Chip all day and all night. Get a bucket and 50 balls. Chip till your hands bleed. Hit high chips, low chips and you will be a better player because of it.