MCTS moveToLeaf() loops for ever

[fmicheloni]

Hello everybody,

I'm trying to reuse this codebase for another game in which pieces can move freely on the board. At a certain point, during the first game, the method moveToLeaf() in the class MCTS starts looping for ever.

It seems like the condition while not currentNode.isLeaf(): is never satisfied.

Do you have any hint for finding why this issue occurs?

Thank in advance,

Fabrizio

P.S.: see my fork for full code -> https://github.com/fmicheloni/DeepReinforcementLearning

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EDIT:

Here a few logs of what's happening:

2018-04-07 13:57:44,052 INFO PLAYER TURN...-1
2018-04-07 13:57:44,052 INFO action: 192 (3)... N = 0, P = 0.235297, nu = 0.000000, adjP = 0.235297, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,053 INFO action: 211 (1)... N = 0, P = 0.257799, nu = 0.000000, adjP = 0.257799, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,053 INFO action: 122 (3)... N = 0, P = 0.252349, nu = 0.000000, adjP = 0.252349, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,053 INFO action: 123 (4)... N = 0, P = 0.254554, nu = 0.000000, adjP = 0.254554, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,053 INFO action with highest Q + U...192

2018-04-07 13:57:44,053 INFO PLAYER TURN...-1
2018-04-07 13:57:44,053 INFO action: 190 (1)... N = 0, P = 0.209210, nu = 0.000000, adjP = 0.209210, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,053 INFO action: 102 (4)... N = 0, P = 0.196694, nu = 0.000000, adjP = 0.196694, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,054 INFO action: 118 (6)... N = 0, P = 0.182340, nu = 0.000000, adjP = 0.182340, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,054 INFO action: 122 (3)... N = 0, P = 0.205482, nu = 0.000000, adjP = 0.205482, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,054 INFO action: 123 (4)... N = 0, P = 0.206274, nu = 0.000000, adjP = 0.206274, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,054 INFO action with highest Q + U...190

2018-04-07 13:57:44,054 INFO PLAYER TURN...-1
2018-04-07 13:57:44,054 INFO action: 192 (3)... N = 0, P = 0.235297, nu = 0.000000, adjP = 0.235297, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,054 INFO action: 211 (1)... N = 0, P = 0.257799, nu = 0.000000, adjP = 0.257799, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,054 INFO action: 122 (3)... N = 0, P = 0.252349, nu = 0.000000, adjP = 0.252349, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,055 INFO action: 123 (4)... N = 0, P = 0.254554, nu = 0.000000, adjP = 0.254554, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,055 INFO action with highest Q + U...192

2018-04-07 13:57:44,055 INFO PLAYER TURN...-1
2018-04-07 13:57:44,055 INFO action: 190 (1)... N = 0, P = 0.209210, nu = 0.000000, adjP = 0.209210, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,055 INFO action: 102 (4)... N = 0, P = 0.196694, nu = 0.000000, adjP = 0.196694, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,055 INFO action: 118 (6)... N = 0, P = 0.182340, nu = 0.000000, adjP = 0.182340, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,055 INFO action: 122 (3)... N = 0, P = 0.205482, nu = 0.000000, adjP = 0.205482, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,056 INFO action: 123 (4)... N = 0, P = 0.206274, nu = 0.000000, adjP = 0.206274, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,056 INFO action with highest Q + U...190

2018-04-07 13:57:44,056 INFO PLAYER TURN...-1
2018-04-07 13:57:44,056 INFO action: 192 (3)... N = 0, P = 0.235297, nu = 0.000000, adjP = 0.235297, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,056 INFO action: 211 (1)... N = 0, P = 0.257799, nu = 0.000000, adjP = 0.257799, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,056 INFO action: 122 (3)... N = 0, P = 0.252349, nu = 0.000000, adjP = 0.252349, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,056 INFO action: 123 (4)... N = 0, P = 0.254554, nu = 0.000000, adjP = 0.254554, W = 0.000000, Q = 0.000000, U = 0.000000, Q+U = 0.000000
2018-04-07 13:57:44,056 INFO action with highest Q + U...192

Those two actions keep looping.