Back in September, I ruminated on when an extension for Giancarlo Stanton might look like, and a run through the numbers gave me an estimate of $300 million over 12 years. The Marlins, reportedly, are negotiating a deal with Stanton that could be worth as much as $325 million over that same time period, so it seems like the estimates in that post weren’t too far off.

Except they kind of were, because I just eyeballed the projections and decided to be a little conservative, so the calculations were based on Stanton starting out from a +5 WAR level. Stanton’s actual Steamer projection is for 2015 is up on the site now, and it has him as a +6 WAR player for 2015, suggesting I maybe underestimated his expected value by a full win each year. Here’s the same table from that post, just starting from a +6 WAR base instead of a +5 WAR platform.

Year	Age	WAR	$/WAR	Value	10% Discount
2017	27	6.0	$7.00	$42.00	$37.80
2018	28	6.0	$7.40	$44.40	$39.96
2019	29	6.0	$7.70	$46.20	$41.58
2020	30	5.5	$8.10	$44.55	$40.10
2021	31	5.0	$8.50	$42.50	$38.25
2022	32	4.5	$8.90	$40.05	$36.05
2023	33	4.0	$9.40	$37.60	$33.84
2024	34	3.5	$9.80	$34.30	$30.87
2025	35	3.0	$10.30	$30.90	$27.81
2026	36	2.5	$10.90	$27.25	$24.53

That projection values his 10 free agent years at a total of $390 million, and doesn’t include the payments he’s basically already guaranteed through arbitration. Toss in another $35 million for the two seasons before the 10 year extension kicks in, and this would suggest a value of $425 million, $100 million more than the Marlins are reportedly offering.

Yeah, I know, it sounds insane. I don’t think Stanton’s worth $425 million either. For one, the aging curve is probably not aggressive enough, especially for a guy his size with a history of knee problems. If we start his decline phase a couple of years earlier, having him drop from +6 WAR to +5.5 WAR at age-28, then the trickle-down has him end up at $313 million for the 10 free agent years, which would put him around $350 million over the life of the deal. Still a bit more than the rumored price, but definitely closer, and probably a bit more reasonable.

The other key we haven’t talked about is a potential opt-out, and how that might affect the valuation. Opt-outs are a way of giving the player non-monetary value in exchange for a lower AAV, and if the Marlins include one in an extension for Stanton, it could help them drive salaries down. Given the Marlins history of selling off players not too long after signing them, I’m guessing Stanton will demand either (or both) a no-trade and an opt-out, giving him the leverage to decide where he goes if he wants to get out of the deal.

If the opt-out is early enough in the deal, making Stanton’s commitment to the Marlins far shorter, then it could give him enough additional value to take less than the $30 million AAV he’s pretty clearly worth. We’ll do a full rundown on the deal when it’s done and the details are known, but it sounds like Stanton’s going to get a monster contract, and he deserves it.