(CBS) John Fox now holds the worst winning percentage among coaches in Bears franchise history after a 15-14 loss to the 49ers on Sunday.

That setback dropped the Bears to 12-32 in the Fox tenure that spans three seasons. That’s a winning percentage of .2727, which is a shade worse than what Abe Gibron produced from 1972-’74. In that span, Gibron led the Bears to a 11-30-1 record, good for a .2738 winning percentage.

George Halas is the Bears’ all-time winningest coach, by way of total wins and winning percentage if we use modern calculation methods. He was 318-148-31 for what Profootballreference.com officially recognizes as a .682 winning percentage, as the NFL didn’t count ties as a half-win/half-loss in winning percentage until after 1972. By the standards of ignoring ties, Bears coach Ralph Jones officially has a .706 winning percentage by going 24-10-7 from 1930-’32.

If ties were factored into the equation for every Bears coach under the modern method, Halas would have a .6710 winning percentage that ranks as the best in franchise history. Jones’ winning percentage would then drop to .6707.