[barmar]

steve2005, on 2021-September-22, 14:35, said:

And they are all wrong!

Anyone who doubles on this type of hand needs to check off the box "minimum off-shape take-out doubles" on their ACBL cc but of course none of them do.

Note that ACBL made this non-alertable many years ago.

The problem is that most of the people who make these doubles don't even realize that they're off-shape. They've either forgotten or were never taught that T/O doubles imply certain shapes, not just opening values.

This style seems to be increasingly popular, maybe as a necessary defense to light openings. For some reason, they don't result in disasters like this one often enough for players to learn not to do it.

[DavidKok]

To the best of my knowledge these light offshape doubles are strong against Precision-type systems, but fare worse against natural bidding systems. Personally I attribute their popularity more to ease of memory ("if you have an opening hand, double" is very satisfying and easy to remember when just learning the game) than to effectiveness.

[Winstonm]

nullve, on 2021-September-22, 17:28, said:

Exclusion advances to double of one-of-a-suit were also part of Roman Club at some point.

This was in Oklahoma City, and we had a older kibitzer - Chuck - who was enraptured by the Roman System so to humor him we let him tell us how he thought it should go and adopted the double and exclusion part just for fun. It was remarkably effective. But then we only played it in about 3 sessions at the local club before the director asked us not to play it anymore so long term we have no data on how good or bad it really wood be.

[pescetom]

DavidKok, on 2021-September-24, 13:54, said:

To the best of my knowledge these light offshape doubles are strong against Precision-type systems, but fare worse against natural bidding systems. Personally I attribute their popularity more to ease of memory ("if you have an opening hand, double" is very satisfying and easy to remember when just learning the game) than to effectiveness.

Around here they were near universal until a few years ago, and yet most bidding systems here are basically natural. Any convention played reasonably well will work, even if out of its context (I imagine that strength-based doubles originated playing Rubber for money, where they make more sense than at MP).

[blackshoe]

steve2005, on 2021-September-22, 14:35, said:

Someone has taught them to double on all 13 pt hands.

More likely someone taught them that they need an opening hand to make a takeout double, and they misunderstood what they were taught.