As Mike only has 4 full NHL seasons under his belt, I decided to start with his first full season and use Hatcher's seasons at the same age (so age 21-24).
Obviously, Mike's rookie season point totals don't compare to anything he's produced since then, but as far as development goes, it's important. From age 21 on, Hatcher is the more consistent of the two in offensive productivity. But even with a slow rookie season, Green manages to out-produce Hatcher (+6G, +2A in only 3 more games). It's also interesting to note that something important occurred after the 1989-1990 season that may have directly led to Hatcher's 20 point increase: the departure of top defender, Scott Stevens.
But Mike is THE man on the back line in DC these days and has been for 3 seasons. The big question is, what kind of production can we expect from him in the coming seasons? Let's take a look at Hatcher's age 25-27 seasons (his last 3 in a Caps jersey):
HATCHER (NEXT 3 SEASONS)
Looking at Hatcher's next 3 season brings his 34 goal season into play (the same season Al Iafrate and Sylvain Cote also netted 20+ goals), which led all defenders. But that same season, Hatcher also led in league in goals against while he was on the ice (162) while only managing to be the 7th most productive defenseman in the league. Kevin's goals seemed to come at the expense of his defense, something Green critics often point out.
In the end, it's really no contest. Kevin Hatcher was never considered the best defenseman in the league while Mike Green has done plenty to strengthen his case as the best. Mike Green has already led the league in goals and points by a defenseman for two consecutive seasons. As his maturity and understanding of the position increase (and all signs indicate that NHL defenders take some time to fully grow into the position, especially defensively) we could see some impressive offensive numbers for Mike in the coming seasons (and hopefully some on the defensive end as well).