The Exchange
Basketball-Reference's Houston, Milwaukee and league transaction logs agree that the Rockets sent John Block to the Bucks on September 12, 1971 for Dick Cunningham. The trade is unusually useful for hindsight work because both acquired players had short first stops and both were moved again within roughly a year. That makes direct production only part of the story. The better comparison includes how each club converted the player afterward, while avoiding the common mistake of crediting an entire later multi-asset trade to only one outgoing piece.
Houston Return
Cunningham gave Houston the stronger direct first-year production. In 1971-72 he appeared in 63 games, totaled 720 minutes and finished with 171 points and 243 rebounds. He was a low-usage reserve center rather than a major rotation player, but he still gave the Rockets far more court time than Block gave Milwaukee. Houston then sold Cunningham's player rights back to the Bucks on September 18, 1972. The sale amount is not preserved in the Basketball-Reference transaction ledger, so the downstream cash is treated as real but unpriced rather than assumed to be trivial or substantial.
Milwaukee Return
Block played only 11 games for Milwaukee in 1971-72, totaling 156 minutes, 55 points and 55 rebounds. His direct Bucks production was therefore much smaller than Cunningham's Houston season. Milwaukee did not simply lose the asset, however. On December 13, 1971 the Bucks traded Block and a 1974 second-round pick to Philadelphia for Wali Jones. Jones then played 48 games for Milwaukee in 1971-72 and 27 more in 1972-73, giving the Bucks guard depth on two strong teams. That conversion is meaningful, but Block was only one part of the outgoing package, so the source-backed grade assigns him partial rather than full credit for Jones's 75-game Milwaukee tenure.
Hindsight Comparison
Houston wins the direct production comparison: Cunningham gave the Rockets 63 games and 720 minutes, then generated an unpriced cash return when his rights were sold back to Milwaukee. Milwaukee's immediate Block return was only 11 games. The Bucks regain ground because Block helped produce Wali Jones, whose two Milwaukee seasons added substantially more usable minutes than Block himself. Yet that later trade also cost a 1974 second-round pick, which prevents Jones from being treated as pure Block-derived value. The result is a narrow Milwaukee advantage on total traceable basketball value, not the large gap suggested by the older legacy D-/B+ grade split.
Final Verdict
Bucks Win, B/B-. Milwaukee receives a B because Block's own stay was brief but he helped produce Wali Jones, a useful guard for 75 Bucks games across the next two seasons. Houston receives a B- because Cunningham supplied 63 games of reserve-center minutes and later generated cash when his rights were sold back to Milwaukee. Confidence is medium-high: the player exchange, Cunningham's production, Block's production and the Jones conversion are well documented, while the Cunningham sale amount is unresolved and Jones cannot be attributed entirely to Block because Milwaukee also sent a future second-round pick. The verdict reflects only verified transaction terms and realized team value.