This was played 3 times

+660 3NT by north making 11 tricks

+600 3NT by north making 9 tricks

+110 3C by south making 9 tricks

At the next table North and East hands held 12 & 14 cards. The wrong card was transferred back resulting in exchange of D8 and H5.

After this results were

+150 1NT by N, 9 Tricks

+120 1NT by N, 8 Tricks

-100 3H by N, 8 Tricks

-200 (twice) 4H by N, 8 Tricks

-200 3C by S, 7 Tricks

-300 (twice) 4H by N, 7 Tricks

ALSO an average would be required by an east-west pair (N/S vacant at one table).

On the night I ruled that no scores should be awarded for this board. This seems hard on the pairs who scored well both before and after the foul-up. But the changed spot cards make the choice of Hearts as trumps pretty routine (but most unlikely to achieve a game score).

The way I thought it might be scored was to treat it as two separate boards - board 13 before fouling and board 13F after fouling.

Considering the north-south pairs only, for board 13 there were scores of +660, +600 and +110. Pairs who "missed this board by sitting out or by playing 13F" would be awarded an average of +460.

Playing the fouled board 13F resulted in N/S scores of +150, +120, -100, -200 (3 times) and -300 (twice). Pairs who "missed this board" would be awarded an average of -130.

Adjusted scores would be for N/S who played 13

+660(-130)=+530

+600(-130)=+470

+110(-130)=-20

and adjusted scores for N/S who played 13F

+150(+460)=+610

+120(+460)=+580

-100(+460)=+360

-200(+460)=+260 (3 times)

-300(+460)=+160 (twice)

With negated scores for their opponents.

AND the E/W pair who missed the board entirely would be awarded -330. (+330 being the total of the averages for N/S for these two configurations)