So, let's break this down. Were the Mets the better option? Statistically speaking, no question about it. Citi Field is a pitcher's dream. Look what it did to David Wright's power. However, don't sell Nationals Park short.
According to MLB Park Factors, it's right in the middle of the pack. And there were actually less home runs hit this year at Nationals Park than at Citi Field, if you can believe it. The Mets and Nats were both terrible defensive teams in 2009, but part of that has to be due to the perfect storm of injuries the Mets had to endure this season.
Defensively, the Nats will be better than they were last year, which is important for someone like Marquis who pitches to contact. Marquis' groundball rate in 2009 was 56%, a career-high. On the Rockies, Marquis had a strong middle infield behind him in Troy Tulowitski and Clint Barmes. He also had solid corner infielders in Todd Helton and Ian Stewart/Garrett Atkins. Brad Hawpe and Dexter Fowler weren't terrific in the outfield, but Seth Smith, Carlos Gonzalez, and Ryan Spilborghs were all very good.
One significant upgrade Marquis will have defensively is at catcher. I wouldn't call Yorvit Torrealba and Chris Iannetta slouches, but between them they only threw out 20% of baserunners who ran on them in 2009; that's well under league average.
On the Nats, Marquis will be working with one of the greatest defensive catchers of all time: Ivan Rodriguez. Pudge may be past his prime and off the juice, but in 2009 he threw out 35% of baserunners who ran on him in 115 games. For his career, he's thrown out 46% of baserunners. Marquis will also be pitching to up-and-comer Jesus Flores, whose scouting report describes him as a good receiver who has a "great arm that can singlehandedly curb the running game."
In addition, Marquis will benefit from Ryan Zimmerman's play at the hot corner. Zimmerman won a Gold Glove for his efforts at third base this year, but don't be fooled by Gold Gloves generally only being awarded to offensive players. Zimmerman is an outstanding third baseman.
In the outfield, Marquis will have Nyjer Morgan patrolling center field. Morgan can go get 'em with the best of them. Morgan is definitely an upgrade over what Marquis had last season. I assume Justin Maxwell will also log some innings in the outfield in 2010. If so, he projects to be a good outfielder.
Now comes the bad. I love Adam Dunn, but he is an awful defensive baseball player. Doesn't matter where you put him. He is a liability at first base and in the outfield. With Nick Johnson out of the picture, Dunn will primarily play first base. Josh Willingham and Elijah Dukes also don't bring much to the table defensively, although Dukes could still develop.
Marquis' middle infield will, in all likelihood, be a downgrade from what he had with the Rockies. Rookie Ian Desmond projects to start at shortstop while veteran Cristian Guzman will be moved to second base. The Nationals are said to be interested in second baseman Orlando Hudson. Hudson is a bona fide Gold Glover and is a groundball pitcher's best friend.
To summarize: Pudge, Flores, Zimmerman, and Morgan are all defensive upgrades over what Marquis had last year. One corner outfield position could be stabilized with Maxwell while the other will almost certainly suffer. First base with Dunn is always an adventure, and the middle infield is still a question mark. Marquis will also have a lot less run support than he had with the Rockies.
One cool thing about this move is Marquis will be the elder statesman on the Nats' rotation. This means he could very well become Stephen Strasburg's mentor. Strasburg's off-the-charts ability is well-documented. I believe Jordan Zimmerman will also emerge as a quality starter. John Lannan is a proven young southpaw whose career ERA+ is 108. Add Marquis into the mix, and you've got a decent rotation 1-4, assuming Strasburg sees time in The Show next season.
I'm not going to lie. New York would have been neat. Obviously, it's a much bigger market, and Marquis grew up there. With the Nats, Marquis' remarkable postseason streak of 10 years is now in serious jeopardy, as is his 6-year run of 11 or more wins per season.
Coming into 2009, many thought Marquis would struggle pitching at Coors Field. That proved not to be the case, as his 3.92 ERA there demonstrates. I wouldn't count on the Nats vying for a playoff spot, but consider the turnaround the Seattle Mariners had last year. In 2008, they won 61 games. Last year, they won 85 games. Maybe, just maybe, the Nationals can also turn it around. And maybe Marquis can help them do it.