Just as playing with hand entry can help correct over-reaching in backstroke, playing with hand entry can help correct "crossing the centerline" in freestyle.
How to Do It:
1. Push off in streamline and start swimming freestyle with a REALLY wide entry. You want to exaggerate this, so your hands should enter at about the level of your waist.
2. As you swim down the pool, change the position of your hand entry just slightly on each stroke. By the end of the length, your hands should be entering straight ahead or even a little bit wider than your shoulders.
3. Take a short break, then repeat.
How to Do It Really Well (the FIne Points):
1. Swimming with your arms this wide will probably feel horrible, because you aren’t getting a very good "catch" on the water.
2. As your hand entry inches higher, try to FEEL for the entry point where you start to get a good catch. This is probably where you want to be when you swim freestyle.
3. The drill may reveal that a wider entry point is more productive than your "normal" entry point.