this is how I know....

[cracicot]

I tend to bid early for 1st few rounds until just 2 bidders left ,then when he thinks he's in the lead and i havnt bid he thinks ive give up then bang last second try to win !!! but lack of tokens means I try not to go over 3 or 4 rounds !!!!

This is a strat that everyone uses for the most part. AS you get up in levels, these tricks dont work as often, or at all.