Table 1.

Experimental design: Treatments and number of pairs

Designation	Constituent game	Matching protocol	No. pairs (observations)
Single 1	1	Single-play	26 (26)
Single 2	2	Single-play	26 (26)
Repeat single 1	1	Repeat single play*	24 (360)†
Single 1 exp	1	Single-play	17 (17)
Same 1	1	Repeat same pairs	22 (440)
Same 2	2	Repeat same pairs	23 (460)
Random 1	1	Repeat random pairs and roles	24 (480)†
Random 2	2	Repeat random pairs and roles	24 (480)†

^*Each player plays each counterpart exactly once, with role alternating between player 1 and 2. 

^†Sessions consist of 12 players, 6 pairs matched repeatedly. Others consisted of at least 8 players.