The Bill trees have league covered

There is no denying the impact on the coaching world that Bill Walsh and Bill Parcells have had. The evidence is apparent as the NFL playoffs begin.

All12 of the coaches have some sort of tie-in to either threetime Super Bowl champion Walsh or two-time winner Parcells. Yes, all 12.

Some are direct: New England’s Bill Belichick, New Orleans’ Sean Payton and the Chargers’ Anthony Lynn were assistants under Parcells.

Other affiliations on the coaching tree go out on a bit of a limb. The Colts’ Frank Reich worked for Doug Pederson, who coached under Andy Reid, who worked for Mike Holmgren, who was a Walsh protege.

As Bob Glauber, the NFL columnist at Newsday points out, all the connections are legitimate. Glauber’s recent book, Guts And Genius, is all about not only Walsh and Parcells, but Washington’s Joe Gibbs. The subtitle of the book tells it all: The story of three unlikely coaches who came to dominate the NFL in the ’80s.

“As I was researching the book, I discovered how those two coaches really concentrated on helping other coaches,” says Glauber, the president of the Pro Football Writers of America.

Walsh disciples as George Seifert, Mike Shanahan, Mike Holmgren and Pederson have won Super Bowls.

After next month’s big game in Atlanta, 18 of the last 19 Super Bowl champions will have some affiliation with those two Bills.

Here’s the breakdown on the other head coaches in this year’s playoffs:

Seattle’s Pete Carroll: coached with 49ers under George Seifert, who was Walsh’s defensive guru in San Francisco

Dallas’ Jason Garrett: worked for Nick Saban, who coached under Belichick.

Baltimore’s John Harbaugh: Reid’s special teams coach. Los Angeles Rams’ Sean McVay: was on Shanahan’s staff.

Chicago’s Matt Nagy: offensive co-ordinator for Reid.

Houston’s Bill O’Brien: worked for Belichick.

Philadelphia’s Pederson: was assistant coach under Reid.