When seeking value on betting lines and predicting fantasy football outcomes, the difference between success and failure can come down to a few key matchups that can have a large impact on the final outcome of those games.

Every game each week is decided by the combination of numerous matchups, but each week, some matchups matter more than others. The aim of this series is to identify a few key matchups every week that will likely have a large impact on the final outcome of select games.

Without further ado, here are three Week 15 matchups to look forward to.

Drew Lock vs. Kansas City Defense

Denver Broncos rookie quarterback Drew Lock is 2-0 to start his NFL career, after defeating the 4-7 Los Angeles Chargers and the 8-4 Houston Texans in the past two weeks. He had an 84.5 quarterback rating against the Chargers and then went off against the Texans.

Lock completed 81.5% of passes for 3 touchdowns, a 136.0 quarterback rating, and 11.4 yards per attempt in Houston. Those numbers were all inside the top 25 in terms of single-game statistics by any quarterback this season, and it was just Lock’s second professional start. He is the first rookie in the Super Bowl era to throw for over 300 passing yards and 3 passing touchdowns in his first career road start. His 136.0 quarterback rating was the fifth-highest by a rookie quarterback in any of his first three careers starts.

Lock will face the toughest challenge of his young career this week against his hometown team, the Kansas City Chiefs. The Chiefs rank 5th in numberFire’s Adjusted Defensive Passing Net Expected Points (NEP) per play, while the Chargers rank 19th and the Texans rank 25th.

In the past three weeks, Kansas City’s defense ranks top-six in opponent completion percentage, passing touchdowns, quarterback rating, and points allowed after playing against Philip Rivers, Derek Carr, and Tom Brady.

Kansas City is 9-1 against rookie quarterbacks with a +13 point differential per game in the Andy Reid era (since 2013), including 4-0 with a +15 point differential per game at home. The last rookie quarterback to face the Chiefs was Lamar Jackson last season -- it was Jackson’s only loss as a starter in 2018.

After growing up just outside of Kansas City as a Chiefs fan, Lock will start his third career game in Arrowhead as the quarterback for a division rival. Lock and the Broncos have impressed the past two weeks, but Patrick Mahomes and the Chief’s stingy pass defense will be one of the toughest games of the season for Denver and its young quarterback.

Arizona Rushing Offense vs. Cleveland Defense

The Arizona Cardinals have faced a brutal schedule of opposing defenses in the past two months. Arizona’s past five opponents all ranked inside the top-10 in Adjusted Defensive NEP per play, and its past seven opponents all ranked top-11 in Adjusted Defensive Rushing NEP per play. Despite this, the Cardinals rank 12th in Adjusted Offensive NEP per play and 2nd in Adjusted Offensive Rushing NEP per play.

Arizona’s rushing offense, in particular, has remained so efficient despite a difficult schedule and a poor offensive line (ranks 22nd in adjusted line yards, per Football Outsiders), because of head coach Kliff Kingsbury’s play calling.

Kingsbury’s air-raid philosophy aims to use as much of the field as possible and spread out receivers. The Cardinals use 10 personnel (one running back, zero tight ends, four wide receivers) on 35% of its plays -- no other team uses 10 personnel on more than 9% of its plays (per Sharp Football Stats).

As a result of spreading out its receivers as opposed to bunching up tight ends near the line of scrimmage, Arizona running backs face loaded boxes (eight-plus defenders near the line of scrimmage) far less often. David Johnson, Arizona’s leading rusher this season, has faced a loaded box on just 5.6% of his carries, which ranks 45th among 46 qualifiers (per Next Gen Stats).

Thanks to facing few loaded boxes, as well as Kingsbury’s creative play designs and the threat of quarterback Kyler Murray (mobile quarterbacks make running backs more efficient), Arizona has been able to find success on the ground. As noted, the Cardinals rank second in Adjusted Rushing NEP per play, but they also rank third in explosive run rate (per Sharp Football Stats).

Arizona’s explosiveness on the ground is a testament to Kingsbury’s offensive design rather than one running back being particularly talented. For example, Devin Singletary ranks 1st in explosive run rate, while Frank Gore ranks 55th. Both play for the Buffalo Bills, but Singletary is an exciting rookie while Gore is near the end of his career. But in Arizona, running backs David Johnson (in Weeks 1-6 prior to his injury), Kenyan Drake (excluding his games as a Miami Dolphin), and Chase Edmonds all rank inside the top-24 in explosive run rate among 67 qualifying running backs.

After facing such a tough schedule of opposing defenses the past several weeks, Arizona will play some easier opponents to end the season, starting this week against the Cleveland Browns. Cleveland ranks 28th in Adjusted Defensive Rushing NEP per play and 29th in explosive run rate allowed.

Kenyan Drake is expected to continue to see the bulk of carries for the Cardinals on Sunday. Drake has played at least 64% of offensive snaps in each of his five games with Arizona since he was traded from Miami at the deadline. Neither Johnson or Edmunds have played more than 44% of snaps since Drake’s arrival, as the two of them continue to recover from their respective injuries. It could turn into a three-headed backfield, but for now, Drake should be the main beneficiary of Arizona’s rushing matchup against the Browns.

Duck Hodges vs. Buffalo Defense

Devlin Hodges is another rookie quarterback who has impressed in recent weeks but faces a difficult matchup this week. Hodges, undrafted out of Samford University, is 3-0 as a starter this season for the Pittsburgh Steelers. He’s played in five total games and would rank third in completion percentage, third in yards per attempt, and ninth in passer rating among qualifying quarterbacks this season.

Hodges’ three starts came against the Chargers (19th in Adjusted Defensive Passing NEP per play), the Cincinnati Bengals (29th), and the Cardinals (31st). Those teams currently have a combined 9-29-1 record. This week, Hodges will face the 9-4 Buffalo Bills, which ranks seventh in Adjusted Defensive Passing NEP per play.

Buffalo’s defense ranks top-three in passing yards per game, passing touchdowns per game, yards per attempt, and passer rating allowed to opposing quarterbacks this season. The Bills faced an easy schedule to begin the season but proved itself the past two weeks when it beat the Dallas Cowboys 26-15 in Dallas and lost just 24-17 to the Baltimore Ravens. The Ravens and Cowboys rank first and second, respectively, in Adjusted Offensive NEP per play.

While Hodges has played efficiently, he hasn’t put up impressive cumulative statistics, as he as attempted just 20, 21, and 19 passes in his three starts. The Steelers have a massive 62% run rate when Hodges starts -- for context, Baltimore leads the league with a 55% run rate this season (per Sharp Football Stats).

It’s likely that Pittsburgh will try to continue to rely on their running game and third-ranked defense, especially considering that Buffalo ranks 7th against the pass and 23rd against the run in terms of Adjusted Defensive NEP per play. If Hodges plays well enough to put some points on the board in what is the lowest projected game total of the week (36.5), he’ll be the first undrafted rookie to win his first four careers starts in NFL history.