Spitballing a Paul Goldschmidt contract extension

The topic came up when Derrick Hall spoke to Arizona Sports yesterday, and it does not appear to be something the team feels there's any urgency to address.  "The great thing about Goldy — and we haven’t sat down to discuss either his contract or when we will address it again — and it says a lot about him.  Goldy is not one who’s pushing for it. Goldy has never expressed any sort of disappointment or discouragement nor has his camp at all, and that’s really a credit to him." This makes sense: he's under team control for another four seasons, and even the cost in the final year - a team option of $14.5 million for 2019 - seems almost laughably good value.

But it's worth noting that Goldie will be 32 when the contract ends, likely on the down side of the aging curve. If we're to try and figure out what he might get paid, there are several factors which play into the calculation. first expressed here by shoewizard - we already did this kind of thing when we were analyzing Zack Greinke's contract. There are four variables you need to plug in to the spreadsheet: a starting WAR, an expected rate of decline, the cost per win, and a rate of inflation for the cost. You can then figure out how much value the player will represent over the expected period of the deal.

How good will Goldschmidt be in 2020?

We have four full years worth of Goldschmidt to this point, covering his age 24-27 seasons, and he has been worth 23.8 bWAR - that's good enough for ninth all-time among first-basemen. Let's look at the three above and three below him on that leaderboard, and drop Frank Thomas, who was more or less exclusively a DH after his age 29 season. How did the others on the chart age? The following chart shows their value for each season the rest of their career or through age 38, whichever came first, and the average value of all those who played at that age.

There are a few ways Goldy's career could track from the end of the current contract. The upside is likely Musial, who was worth 32.3 bWAR over the five seasons covering ages 32-36. The downside is Helton, who is perhaps the poster-child for caution, having fallen off dramatically, particularly after age 35 - over the remaining four seasons of his career, the Toddfather was worth just 2.4 bWAR, while taking home just shy of $48 million. Of course, there's something to be said for him as a Goldschmidt comparison: the undeniable face of the franchise, getting paid later, after having been insanely good value previously (age 26-30, Helton was worth 37.4 bWAR and cost $33.45m).

The chart above plots the average bWAR of these players against their age. Obviously, we're talking about a small sample size, but based on the above, it does seems possible we may be enjoying the best of Goldie at the present time. Not to say, in the slightest that he'll become a DFA candidate, more that the insane level of production we saw last year is extremely hard to maintain. Among first basemen In the integrated era, only Albert Pujols has managed more than one season worth eight bWAR or better; Goldy last year was at 8.8.

Looking at ages 32-36, we find the average value was 20.5 bWAR, and this isn't too far away from Jeff Bagwell, who may be the best comparison for Goldschmidt among these five: both men had won a Gold Glove and were good base-runners. From ages 24-27, Bagwell's line was .309/.398/.537 with 50 SB, while Goldschmidt's has been .303/.400/.539, with 63 SB. Over the four subsequent seasons, which mirror the time left on Paul's current contract, Jeff was worth 28.9 bWAR, and I think we'd all happily settle for that. Further out, there was something of a decline, but from ages 32-36, Bagwell was still worth 22.7 bWAR.

If you want to go with the average model, you can use a value of 5.0 bWAR for age 32; if you take the Bagwell line, use 5.5 instead. Both models can then have the standard half-WAR decline per season there after, and you'll get a total for the 32-36 seasons of 20 and 22.5 bWAR respectively.

How much will a win be worth in 2020?

The above suggests we might be looking at a five-year contract, covering 2020-24 (Goldschmidt's age 32-36 seasons) with Paul perhaps producing in the 20-23 bWAR range over its course. The other big factor is attempting to estimate the value of a win over that point. A couple of years ago, Dave Cameron estimated a win in free-agency as being worth $7 million, and if we estimate 7% inflation since, that would become $8 million now. This is one of the benefits of arranging the deal in the present. A figure can sound very high in the present day, and be happily accepted by a player, may be market value in 2029, and a positive bargain by 2024.

Witness the following table. Given a current cost of $8 million per win, this shows you what the cost will be for the years 2020 through 2024, given various standard rates of inflation, and what that makes the average over the five seasons in question.

You can see the radical difference in average cost, depending on the rate of inflation. Multiple that difference by twenty or more WAR, and you could end up looking at a total variation of $100 million or more, so getting the figure right clearly matters, on both sides. Over-estimate, and teams risk paying over the odds. Under-estimate, and players could sell themselves short.

What figure should we conclude?

The above values can be combined, and the specific results will vary, depending on your particular opinion. At the low-ball end, we have 15 bWAR at a rate of $9.6 million, which would be a $144 million extension for the five year period. At the high-end, 25 bWAR at $14.3 million, which comes in north of $350 million. That's a hell of a gap. Split the difference? 20 bWAR at the recent 7% rate would be $242 million. That would still seem hellaciously high, but time has a way of softening these things. By then, we'll likely have seen Bryce Harper smash all records, perhaps scoring the first $400 million deal.

Other factors will play into the final amount. A hometown discount? By all accounts, Goldie loves it here, and unlike some, it does not appear that money is his sole motivation. He might be perfectly happy to accept a lesser amount than free-market value, to stay where he's happy. On the other hand, the team might feel some desire to reward him for production during his current, severely underpaid contract. We saw something like this when Luis Gonzalez was given a three-year, $30 million extension in March 2003, after having been a four-time All-Star for us, while never earning even $5 million.

If I'd to guess, taking all these factors into consideration I'd not be surprised to see a five-year extension for $175 million, presuming Goldschmidt continues to be among the best players in the game going forward [and I'm fairly confident, health permitting, that will indeed be the case] He's already - and any argument here will likely cease by the end of this season! - the best position player in franchise history, and I think the prospect of him playing anywhere else would trigger a mob, with pitch-forks, immediately to descend on Chase Field.