Question about Bridge observation tensor types.

[zizhang-qiu]

Hi, I read the code in bridge.cc and find the observation tensor only use three types ,

open_spiel/open_spiel/games/bridge/bridge.cc

Line 317 in d8a3bab

if (phase_ == Phase::kPlay) ptr[2] = 1;

open_spiel/open_spiel/games/bridge/bridge.cc

Line 400 in d8a3bab

ptr[phase_ == Phase::kPlay ? 1 : 0] = 1;

However, in bridge.h, four types of observation are declared.

open_spiel/open_spiel/games/bridge/bridge.h

Line 55 in d8a3bab

inline constexpr int kNumObservationTypes = 4; // Bid, lead, declare, defend

[lanctot]

Hi, thanks. @elkhrt any ideas?

[elkhrt]

Yes, this looks like a bug - thanks for reporting it. Line 317 should be something like:

  const bool defending = (partnership != Partnership(contract_.declarer));
  if (phase_ == Phase::kPlay) ptr[2 + defending] = 1;

Do you fancy fixing it?

In general, we've only really used the bidding phase of the bridge implementation, so there may be some small issues with the play phase.

[zizhang-qiu]

Thanks for the reply.
To be honest, I don't know how to fix it on github. Should I create a pull request or something? Are there any tutorials?

[elkhrt]

Yes, submit a pull request. You'll need to sign an contributor agreement also.
There's no OpenSpiel specific tutorial, but plenty of general ones!

[lanctot]

Fixed by PR #1172 . Thanks @zizhang-qiu !

Commit here: 931e39a