Signifant composition dependent index variation has been demonstrated for the hand 16 v 10 at the 3-card level of analysis (this page.) The existence of this 3-card CD variation was suggested by the discrepancy between the 2-card indices and the mean index for the hand.

Such a discrepancy also exists for the hand 16 v 9. Wong gives a mean index for this hand (SD) of +5. Yet he gives CD indices (2-card) of +8 and +9 for 10,6 and 9,7, respectively. Zenfighter, in recent calculations which may have more modern parameters gave indices of +7 for both of these hands (+6.9 and +7.1, again respectively.)

16 v 9, while less frequent than 16 v 10, is nonetheless a very significant hand, at 0.96% of all hands (multideck, Schlesinger BJA.)

I believe a 3-card CD analysis of 16 v 9 would be interesting, and possibly even worthwhile for SD players.

Do you agree, Zen?