I get the quirk with the AVV. Myer's got paid much more early in his deal, so his AVV is way less than his actual salary, now. That part will save the Sox a lot of space on the luxury line, regardless of how the formula works when a team pays the other to take a player. His AVV is $13.8M, but he's making $20M.
It seems fair, that if both teams pay half his salry, it would mean both teams get charged half on the lux tax (about $6.9M each) and not SD $10M and us $3.8M. I'm not saying I know what the rule is, but if it is as you say it is, it clearly lets one team "off the hook" at the expense of the other.
To me, maybe the fairest way is to take the percent of his whole deal SD is giving us, and then apply that percent to the AVV and split it that way, but I doubt that is the way it is, especially since they don't go back and retroactively change the numbers of years in the past, which my suggested way would do.
I hope the number would be $3.8M for us, not $6.9M, but either way, it's a good deal for us, if we get Quantrill and maybe another prospect plus Myers, who I am not writing off, for just $3.8 or $6.( on the lux budget.