Joe Maddon and Bill Belichick are "coaches" of the current championship teams in professional baseball and football respectively.
Maddon won his first in October 2016 for the Chicago Cubs and Belichick won his fifth Sunday, five days ago, for the New England Patriots. Neither played professionally at the "major league" level. Neither has his job based on playing ability. Both are considered thoughtful students of their games.
There's been some talk since Sunday about how the Belichick approach might work in baseball. Some of it centered on going all out to win when the opportunity presents itself. Some was based on Belichick adapting to situations. There was no talk about Maddon coaching an NFL team.
Try to consider this devoid of your feelings about whether you love/hate Maddon/Belichick, Cubs/Patriots.
Traditionally, baseball managers have been former players with "major League" experience but NFL head coaches have either not played in the NFL at all or had been marginal players.
The most recent NFL championship coach who had been a really good player was Mike Ditka: 1985 Chicago Bears defeated the New England Patriots, who, ironically, were coached by Raymond Berry. Both Ditka and Berry are in the pro football Hall of Fame as players. But the NFL has had great coaches who never played in the NFL, including Paul Brown and Vince Lombardi.
In the NFL, Tony Dungy was a starter in all three of his NFL seasons as a player. Dungy is in the football Hall of Fame as a coach: six years with Tampa, seven years, including the 2006 NFL championship with Indianapolis.
Tom Flores was the Raiders starting quarterback 1960-1966, then one year as Buffalo's. Flores was the Raiders coach 1979-1987, winning the championship in 1980 and 1983. Flores then coached Seattle 1992-1997.
Tom Landry was an NFL player 1949-1955 and the first coach of the Dallas Cowboys: 1960-1988. Landry coached the Cowboys to two championships: 1971 and 1977. He's in the football Hall of Fame as a coach.
The Major Baseball League now has more team "managers" who played little, if at all, at the "major league" level. Tony LaRussa won championships in both Oakland (1989) and St. Louis (2006, 2011) and is in the Hall of Fame as a manager. Joe Torre won four as manager of the Yankees (1996, 1998, 1999, 2000) and is also in the Hall of Fame. LaRussa had a brief and insignificant career as a "major league" player. Torre was an All Star and NL MVP in 1971.
Journeyman catcher (1978-1987) Bruce Bochy won three championships with San Francisco: 2010, 2012, 2014. Terry Francona, another marginal "major league" player 1981-1990, won championships with Boston in 2004 and 2007, and, managing Cleveland, lost in seven games in 2016 to Joe Maddon.
Since Torre's last championship in 2000, the best former baseball player to manage a championship team was Ozzie Guillen with the 2005 Chicago White Sox. Guillen was the White Sox shortstop 1985-1997; rookie of the year, All Star 1988, 1990, 1991. That's a much more substantive playing career than any championship NFL coach in at least 50 years, except for Ditka in 1985, with honorable mention to Flores for 1980 and 1983.
Mike Scioscia was a catcher for the Dodgers 1980-1992, playing at least 114 games in ten seasons. Scioscia has manged the Angels 2000-2016, winning the championship in 2002.
OK, that's enough. What would happen if Joe Maddon and Bill Belichick swapped jobs?
Let's assume that each has a fan's knowledge of the other's sport. So this basically becomes a comparison of the relative complexity of the sports.
Belichick would do OK managing the Cubs. Maddon would be swamped as head coach of the Patriots. The Cubs would have some respect for Belichick. The Patriots would have none for Maddon and would either ignore him or openly rebel. Belichick would learn enough, quickly enough to remain afloat. Maddon would drown quickly.
None of this could be any more than conjecture but I think the context of applying Belichick attributes to baseball misses the key matter: baseball is simple, football is complex. It's checkers v. chess. And Belichick is a grand master.