WHERE DO TOPS COME FROM ?.........( Article by Carp )

Ideally, they should come from superior bidding alongside superior card play. A situation where experts manage to cleverly engineer an auction towards an ideal outcome , which creates for them golden opportunities to seize and exploit to maximum effect.
Sadly however in the world of duplicate bridge tops usually arrive as unexpected gifts , courtesy of their opponents ;
- bidding misunderstandings in the bidding 
- gross underbidding and/or bidding 
- careless or inept play of the cards
- costly breaches of the rules ( incurring penalties or damaging restrictions )  
- revokes
- mechanical errors such as pulling out or playing the wrong cards
- crucial lapses of concentration
- magical thinking
- allowing emotions to take over from sound judgement
- an alarming inability to read the cards or piece clues together
Good scores are all to often the result of unforced errors , as in a game of tennis. Too many tops are undeserved, such as  arriving at a ridiculous , impossible slam only to make it against all the odds,  because of woeful and inept defence. If winners are deemed to be the players who make the least number of mistakes , it must also be true that winners  are those who profited most from mistakes committed by opponents than any other pair in the room.