Pardon Patrick Mahomes if he seems to be a novice at explaining the effects of strong defensive play.The Kansas City quarterback has seldom recognized such support. The defense was the weak link last season, when the Chiefs reached the AFC Championship Game largely because of Mahomes and his offensive threats. When he played for Texas Tech, the numbers Mahomes put up — including a record 819 total yards and 734 passing yards in an, ahem, loss — routinely failed to overcome a shoddy defense.However, as the Chiefs (11-4) ride a five-game win streak entering a home game Sunday against the Los Angeles Chargers (5-10), the defense has been key. The unit has allowed 9.6 points on average and four total touchdowns during that stretch , including no TDs in the last nine quarters.”We understand that if we can go out there and put up some points,” Mahomes said, “then they’re going to hold the lead for us, and we’re going to find a way to get a win.”Mahomes’ quick-strike capability enables Kansas City to gamble defensively with different blitzes and coverages that first-year coordinator has Steve Spagnuolo introduced.”You could see the want-to early (this season),” Chiefs head coach Andy Reid said of the defense. “The positive thinking and the want to do the right things, you saw that right away.”Newcomers such as safety Tyrann Mathieu, defensive end Frank Clark and linebacker Terrell Suggs, whom the Chiefs claimed off waivers just last week, bought in immediately and provided leadership. Mathieu was especially helpful improving an aggressive secondary.Meanwhile, Mahomes overcame ankle, knee and hand injuries. After missing two games, he has engineered a team as hot as any except the Baltimore Ravens (11 straight wins), who are assured the top seed in the AFC playoffs.The Chiefs, who clinched the AFC West title in a Dec. 8 win at New England, sit No. 3 in the conference and will play their starters Sunday. They must beat the Chargers and hope for an improbable Miami upset at New England to overtake the Patriots for the No. 2 seed and a first-round playoff bye.