Posted 2019-January-30, 22:37
Not drawing trumps is right, it's not a mistake; it's the right play! You can't afford to draw trumps because your main goal is to set up the spade suit, which may require 2 or 3 ruffs. Where you messed up is later in the play, where you failed to take advantage of the defense helping you out by attempting to cash the CK (always reassess in middle of play in light of unexpected break or developments, possibly modify your initial plan), and not anticipating the danger of a spade overruff. After you get your first spade ruff you should immediately cash CQ and pitch a long spade, this should be pretty safe against robots and most opponents because it's super weird to lead low from Kx doubleton of clubs, and even if the 1 in 500 chance LHO ruffs this it's one fewer spade to ruff and you aren't down yet. You should also note the fall of the SJ on the ruff, which should have woken you up to the danger of a third round overruff (though you should be woke to that even without the honor falling). 5-2 spades is more common than 6-2 diamonds so it's more crucial to ruff third spade high than 3rd diamond high, plus scoring your 2nd low trump in hand prepares for high cross-ruff later.
Finesse or not trick one ... basically when dummy comes down you need to make a plan for how you will get all your tricks. You take the finesse if you think it's part of the best plan, that it's higher percentage than hoping for some other things, if it will gain you a trick if it works. Here, you can see that you can avoid a club loser by pitching on diamonds, so the finesse doesn't really help you in the minor suits. It only helps you if it works AND the diamond pitch helps you in spades, which is only true if the fifth spade is a loser. But at trick one you should be thinking that the fifth spade is likely a winner; after most common 4-3 break if you can ruff spades a couple times the fifth spade is likely to be good, or sometimes you can just give up a 2nd spade to establish the fifth. So eschewing the club finesse is probably right, as you avoid a club loser for sure, and even if it wins, it may not help you at the end(it only helps you on this hand because spades 5-2 offside behind you; if 4-3 or 5-2 the other way the finesse probably doesn't increase your trick count even when it works).
In any case, you should take advantage of BBO making bridge master free, it will improve your play a lot. Also consider reading some books on declarer play, like Root "How to Play a Bridge Hand", Mollo & Gardner "Card Play Technique", to start with.