Becoming familiar with a new system

We played in an Open Pairs event at a sectional on Saturday and ended up sixth overall (gaining 2.5 silver points) for posting 62% and 53% sessions. The somewhat poor performance is, I think, part of becoming familiar with a new system. Our defense is as tight as it was, but we are not yet very good at evaluating hands (as opposed to merely counting high-card points) and making the right bids.

First of all, why bother learning a new system when we were quite comfortable with 2/1? Here are two hands that illustrate the two key benefits (in my mind) of playing Precision.

One reason is that strong hands in the range 16-21 become much easier to bid. For example, this is a hand that partner opened 1C (16+) points, following which we had a pretty natural game-forcing auction to 4H.  Playing 2/1 or SAYC, this hand would be somewhat harder to bid.  You open 1D, hear 1S and now what?  Do you have the right shape to reverse to 2H? Do you have the right shape and strength to bid 2NT? Will you ever discover your 4-4 heart fit?

Dealer: E Vul: None	North ♠ K1074 ♥ Q5 ♦ 1093 ♣ KQJ2
ME ♠ AQJ63 ♥ J1094 ♦ 64 ♣ 75		PARD ♠ 9 ♥ A732 ♦ AKQ8 ♣ A1084
	South ♠ 852 ♥ K86 ♦ J752 ♣ 963
Bidding:	1C*-P-1S-P 1NT-P-2H-P 3H-P-4H	HTML Bridge Hand Layout Creator

This is also an interesting play problem.  How would you play 4H from the West side on the lead of the King of clubs?

Double dummy, 5H should make, but I played it on cross-ruff lines, making only four.  I took the club lead with the Ace, played the ace heart, and three rounds of diamonds, discarding my club. Then, I cashed my ace of spades and planned to ruff three spades in dummy and three clubs in hand to come to 11 tricks.  South over-ruffed the final spade, however, so I got just 10 tricks. I should not have pulled that initial round of trumps. Even though I needed to ruff only thrice, I can use the Ace to avoid the over-ruff at the end. Still, in spite of this misplay, we got a top board, probably because most pairs were in 3NT.

The second reason to play Precision is tied to the first one. Because all strong hands go into 1C, we can now open very light without the fear that partner will hang us.  For example, we stole this hand holding just 15 points between us.  2S making was a clear top:

Dealer: W Vul: NS	North ♠ K ♥ 93 ♦ AKQ9652 ♣ 874
ME ♠ J6542 ♥ A84 ♦ 4 ♣AJ109		PARD ♠ A1073 ♥ J72 ♦ 73 ♣ 6532
	South ♠ Q98 ♥ KQ1065 ♦ J108 ♣ KQ
Bidding:	1S(!) - 2D - 2S - P P - P	HTML Bridge Hand Layout Creator

Note the unsavoury choice faced by South because of my decision to open my 10-point hand. If she makes any strong bid (3S? 3H, if forcing), they'll get to an unmakeable game contract. And if, as here, she doesn't show her points, her partner passes and lets us play a cold contract at the two-level.

We are moving to Precision because it has its advantages. However, we are still not completely at ease with the system, and so we had several bad boards where the system "led us to a bad contract."  The solution in such cases is to be not too rigid, to realize such situations and take a corrective action.  Here, for example, after I opened 1C, and partner bid 2C (8+, game force), we ended up in a contract that was down 3 (4H is also down 3):

Dealer: E Vul: EW	North ♠ A875 ♥ 4 ♦ K95 ♣ K10952
ME ♠ K3 ♥ KJ8753 ♦ AJ10 ♣ A3		PARD ♠ J42 ♥ Q ♦ Q62 ♣ QJ8764
	South ♠ Q1096 ♥ A10962 ♦ 8743 ♣
Bidding:	P-P-1C*-P 2C-P-2H-P 3C-P-3NT	HTML Bridge Hand Layout Creator

I do learn my lessons though, so four hands later, when I had a comparable hand, I was able to take corrective action. Realizing that my hand was not worth 16, instead of opening 1C, I opened 1NT (promises 14-16, no 5-card major) even though I had 5 hearts. Partner transferred to me to spades and we played there, like every other pair in the room.

Dealer: E Vul: EW	North ♠ KQ64 ♥ K87 ♦ KQ42 ♣ 97
ME ♠ A2 ♥ Q10654 ♦ A83 ♣ AQ8		PARD ♠ J10953 ♥ 3 ♦ J65 ♣ K1052
	South ♠ 87 ♥ AJ92 ♦ 1097 ♣ J643
Bidding:	P-P-1NT(!)-P 2H*-P-2S-P P-P	HTML Bridge Hand Layout Creator