What the rest of the AFC West is doing to de-throne the Broncos

Outside of New England, the most dominant team in the NFL over the last few seasons has arguably been the Denver Broncos. Led by the prolific arm of a future first-ballot Hall of Famer in Peyton Manning and an underrated defense, the Broncos have clearly established themselves among the league's elite in recent years.

Since hitting rock-bottom in 2010 with a 4-12 record, the Broncos have won four straight division titles and have posted double-digit wins in each of the last three seasons. Denver has the best regular-season record in the NFL (38-10) since 2012, two games better than the New England Patriots (36-12). They've terrorized the rest of the league with an explosive and record-setting offense that has ranked first or second in points in every campaign with Manning under center.

In that span they've also notably lapped the rest of the AFC West; the next-closest team in terms of wins is the San Diego Chargers, who are barely over .500 (25-23) . The Kansas City Chiefs are actually the last team besides the Broncos to win the AFC West, but have made the playoffs just once since that title season in 2010. Finally, there are the Oakland Raiders, who have taken a permanent residence in the division's basement and have just 11 wins over the last three seasons combined (or one fewer than the Broncos had in 2014).

Perhaps because this seems to be a team in transition with all the coaching changes, the Broncos have been much quieter this winter after last season's free agency spending binge. They have taken some big hits -- losing tight end Julius Thomas, guard Orlando Franklin, safety Rahim Moore and nose tackle Terrance Knighton -- and tried to patch up some holes with a few value signings (tight ends Owen Daniels and Virgil Green, defensive tackle Vance Walker, guard Shelley Smith).

The most significant deal made by the Broncos might have come before the start of free agency, when they placed the franchise tag on wide receiver Demaryius Thomas. The 27-year-old will count more than $12 million against the cap in 2015, but he is worth the high price tag. He is Manning's favorite target and one of the most productive wide receivers in the league. Since 2012, he ranks second in receiving yards, third in receptions and is tied for second in touchdown catches.

San Diego also filled a glaring hole in its receiving corps with the addition of wideout Stevie Johnson. The former 49er should replace the production of slot receiver Eddie Royal, who was a key third-down target last season but left for the Chicago Bears earlier this winter. The Chargers still have some work left to do -- they need a pass rusher after parting ways with Dwight Freeney, and could really use a dynamic running back to bolster a rushing attack than ranked 30th in the league last season.

The Chiefs' most important move of the offseason was probably putting the franchise tag on linebacker Justin Houston, who racked up an NFL-best 22 sacks last season. But the team didn't stop there in addressing its biggest needs. They were among the most aggressive spenders during the first wave of free agency with several impact signings on both offense and defense.

Notably, they gave Jeremy Maclin a five-year deal worth a whopping $55 million, looking to improve an underachieving wideout group that failed to catch a single touchdown pass in 2014. Maclin should give Alex Smith a much-needed playmaker and field-stretching weapon on the outside. Kansas City also shored up its secondary -- a critical position when you play in the same division with Peyton Manning and Philip Rivers -- by re-signing of safety Ron Parker and adding former Raiders safety Tyvon Branch.

With loads of cap room entering the offseason, the Raiders were expected to be very active in free agency and tried hard to land a marquee player, but ultimately came up short. The big-ticket item was the signing of center Rodney Hudson, who will be the league's highest-paid center with a five-year, $44.5 million contract. Although he's not an elite lineman, he should be an upgrade over Stefen Wisniewski.

The most important addition was probably defensive tackle Dan Williams, a massive run-stopper who should help a Raiders defense which allowed 119 rushing yards per game last year. Oakland still needs some impact offensive weapons to surround quarterback Derek Carr. But with plenty of money to spend this winter and a mandate to reach the minimum spending threshold by 2016, the Silver and Black will probably be scouring the free agent wire in the coming weeks.