The tournament is not going well but you are playing the bottom team in your group, so you have expectations of a good win. The first twelve boards have gone reasonably well, with a possible game swing in on a quiet set of hands, when you find yourself with the following hand on board 13:
It is game all. What do you open?
Obviously one (strong) notrump is a consideration. The alternative is to open one club, planning to rebid one spade over a red suit response and hoping that you can get your additional values over. This may lead to an uncomfortable auction, since you will feel obliged to raise partner if he bids one notrump. And if partner responds one notrump initially, then a raise may get you too high.
And if you play transfer responses to one notrump, then there is more reason to open one notrump as a one spade response (whether it shows diamonds or is a wide-range transfer to one notrump) is uncomfortable.
So I think it is unclear what is best.
Have you decided yet?
Well, opening one club is the successful action this time, as your partner is broke and your LHO is going to overcall in spades. It is unlikely that your opponents will find a making spot and you will go positive.
Open one notrump and you may find that your partner tries a Stayman rescue (with 3451 distribution) to uncover your 4-3 spade fit. However RHO, in the balancing seat, finds a double that is left in and you lose -1100 in your best fit.
If your tournament is going badly, guess what actually happens?
So now we have a pair with -1100 on their card and probably -15 imps for the team. Is this just unlucky? When you come to analyse the performance of the team and this pair in particular, do we say that only the numbers count or do we write this off in the 'unlucky' column. You don't get many gifts in world championships so it takes a lot to recover from this when it is engrained in the Butler, just one board reducing your score by -0.1.
Of course the answer is that it depends why you are analysing performance. Is it for objective selection (just use numbers), blame (use the numbers you like) or to seek improvement by identifying weaknesses?