Believe it might be overs and unders, or unders and overs, depending on whether you're a back or a forward, or what the coach says.

3 lengs on 30 seconds
3 lengths on 28 seconds
3 lengths on 26 seconds
3 lengths on 24 seconds
3 lengths on 22 seconds
3 lengths on 20 seconds
4 lengths on 19 seconds
4 lengths on 18 seconds
4 lengths on 17 seconds...
and I don't know what it drops to from there

can someone confirm this?