Dunbar wrote (snip):
"Harry, what you're suggesting will give you the cost of playing JOB with DDB strategy, but not the cost of playing DDB with JOB strategy, which is the example I was using."
The actual return on 9/6/5 DDB using the generated 9/6 JB strategy chart is 99.56%. That's 0.82% off of perfect for that DDB game. This was calculated by selecting the DDB game, loading the JB strategy chart, and evaluating the chart for its actual return.
This method is quick and easy with no hand calculations or approximations, and it can by used for any supported game with the strategy from any other supported game. For a ridiculous example, you could even find the payback for Deuces Wild with TDB strategy.
BTW, the return on 9/6 JB with that same generated chart is 99.54292%, less than 0.001% off of perfect which is as close as you can get without penalty considerations.
Dan