A simple and effective approach, making a proper nuisance of your self without too great a risk of being doubled and going down too expensively, is to bid to the level of the fit. Work out how many cards your partnership hold – putting partner with five cards for the overcall – and bid for that number of tricks.

As you see, your bid does not show any points. In fact the fewer points you have, the more likely the opponents can make a high contract and that your disruptive tactics will pay off.

Take the third hand. You may end up in 4 ♠ with as few as 11 or 12 combined points. You may get doubled and go two down (unlikely more, given your ten-card spade fit plus side singleton). This is normally better Bridge than letting the opponents bid and make a game. However be a tad more cautious (a) if vulnerable (doubled vulnerable undertricks are quite costly) and (b) if very flat. If I was vulnerable and my shape was 5332 not 5431, I’d probably only bid 3 ♠, not 4 ♠.

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