[KiwiBridge]

The other night I played a 10 board Swiss IMPS which was clocked and had 37 tables. The pair we started with, we played again in round 5. Should this happen?

[uday]

Playbacks are normal. Someone once tried to tell me that Danish (no playbacks) is superior to Swiss (playbacks -- or is it the other way around) and maybe it is.

[MickyB]

Danish has playbacks, Swiss doesn't. Which is superior depends upon the number of pairs and the number of rounds. Some use compromise solutions - say Swiss until the final two rounds, then Danish.

[Gerardo]

with a minimum number of participants ( 2^#rounds comes to mind, but seems too much; something related to that, maybe square root?), proper Swiss should be doable from start to end.

[hotShot]

The problem with swiss movements is, that pairs/teams that have already played against their direct competitors, would get weaker opponents in the next rounds. Assume you are first on the list hand have already played against the 2nd-4th in previous rounds. You would now get the pair/team that holds the 5th place as opponent. While the 2nd and 3rd will fight for a close result, you might be able to score big.
This problem gets smaller, if the field is of equal strength (or at least the top 10 pairs) and if the field is big (smaller chance to play a top competitor early).
The number of rounds should be log2( participants) or 2^#rounds = #participants. Note: The number of rounds should not be bigger than that!

#Participants #Rounds
   4                    2
   8                    3
 16                    4
 32                    5
 64                    6
128                   7
256                   8  

So if you have 50 pairs you should play 6 rounds, without replays.

In a danish movement, you always play against your direct competitors, because replays are allowed. This way these competitors won't get easyer opponents, but a weaker pair might pass them, afterscoring big against an even weaker pair. In the worst case, e.g. at MP's 2 paist can always score 50% against each other, and will continue to replay over and over.

In f2f bridge TD's like to combine these methods and play, without replays until the last 1 or 2 rounds, and allow replays during the rounds left. This makes sure you get diferent opponents at the beginning and play your direct competitors at he end.

[Echognome]

It obviously depends on your goals. I'd say in your above example that the 1st place team that has had to play against the 2nd-4th place teams has performed already against tougher opponents than the 2nd-4th place teams have had to. Is the goal to even out the "strength of schedule" (to use a sports analogy) or is just to have an exciting finish (the top pairs fighting it out in the last few rounds). My guess is that the compromise position is trying to do both.

[KiwiBridge]

If it is Swiss then Swiss should apply? Otherwise why not call it Danish?