Tip 144: Compare your cadence

Every time the foot reaches the 6pm position, that's a full rotation. Count it out. 
If the guy in front hits 6pm more often than you, he must be some sort of creep who pays a coach and has a Cervelo tattoo on his down-tube.
If he hits 6pm less often than you, he probably just left the bike shop, his last ride was a plastic tricycle, he has never changed a flat, and he's about to get a cog tattoo on his ankle.

 BONUS TIP: Rarely - nay - almost never, you will meet your cadence soulmate. A cyclist that spins the same as you on the downhills and the ups.  A cyclist in tune with your approach to cycling, likely also your philosophical equal and potential god father to your children.
When you see this cyclist on the road in front of you, you have only one choice. Tighten your grip on the bars, drop the hammer and burn him.