IT'S ALL TOO EASY FOR PLAYERS TO LOSE THEIR COOL WHEN PARTNERS LOSE THEIR WAY........ ( Article by Carp ) 

Let's face it inept partners can drive anyone to blow their stack. How players are meant to keep their cool when partners keep on pressing self-destruct buttons is beyond me. Indeed , over the years I've had to clench my fists, bite my tongue and bottle my anger and frustration because of partner's carelessness and idiocy. How can anyone be expected to cope with a partner who during a session commits the following sins :
1.  Forgets what's on the system card
2.  Hands out advantages to the opponents by bidding and playing cards out of turn
3.  Makes careless discards which then exposes you to an excruciating squeeze
4.  Pulls your excellent doubles into a doomed contracts 
5.  Fails to return a suit which which you were planning to ruff
6.  Fails to cash a winner because of his/her failure to count  
7.  Ignores both obvious and blatantly obvious signals
8.  Always manages to choose grossly inferior lines of play
9.  Forgets to alert artificial opening bids 
10. Leaves in your take-out doubles
11. Misbids distributional two-suited hands
12. Allows suits to be blocked
13. Maroons him/herself from winners in dummy
14. Pulls trumps when cross-ruffing provides the best chance of making tricks
15. Loves to lead out unsupported honours
16. Gifts opponents galactic tops
17. Can never recall the bidding or cards played earlier on
18. Hesitates for ages before passing
19. Selects a card to be played ahead of everyone else
20. Falls into the simplest of traps set by the opponents
21. Misses every opportunity to punish slip-ups by the opponents
22. Goes on walkabouts
23. Can never recognise what declarer is up to
24. Loves to give opponents free get-out-of-jail cards
25. Doesn't know or understand the concept of safety play
26. Over bids on poor hands while underbidding on good hands

Need I go on because in even in these few examples any saint would succumb to flying into a rage invoking the wrath of the zero tolerance enforcement officers , who of course have no idea or sympathy as to what you have had to suffer.