Defenses matter a lot in fantasy football. If you can draft and matchup the right players against sub-par defenses, you have a recipe for success. It’s not as easy as just looking at the best and worst defenses from 2014 though, and that’s why we’re here to help.

In this eight article series, we’re going to take a look at all the defenses in the NFL. We’ll look at whether or not teams have improved for 2015, and dive into the passing and rushing defensive potential of every NFL team, one division at a time.

Today we are taking a look at the NFC West passing and rushing defenses, and their outlook for the 2015 fantasy football season. When this series is over, you will have a great grasp of which defenses to target for plus matchups.

Editor's Note: Stay on top of your draft prep with RotoBaller’s fantasy football rankings, featuring expert analysis, ADPs, and draft insights for both PPR and non-PPR leagues.

Editor’s Note: If you’re looking for a new, awesome, highly customizable and free option for year-round commissioner & dynasty leagues, something more capable than Yahoo, better looking than CBS, and built from the ground up with fantasy football in mind, play free fantasy football with our friends at Fleaflicker. Sign up your league on Fleaflicker, and get a Full Season Premium Subscription for FREE.

NFC West Passing Defense Rankings

Stats listed are: 1) 2014 Pass Defense Ranking per DVOA, 2) Fantasy Points against QBs, 3) Fantasy Points against WRs, per ESPN

Arizona Cardinals

2014 Rankings: 14, 22, 17

The Cardinals secondary played better than their ranking last season. Patrick Peterson and Antonio Cromartie both finished the 2014 season as pro bowlers. Jerraud Powers and Peterson were the 11th best cornerback duo in a supporting role and leading role by adjusted success rate, according to Football Outsiders.

2015 Projected Pass Defense Ranking: Middle of Pack

Losing Cromartie and defensive coordinator Todd Bowles to the Jets will hurt. Peterson is great, but there isn’t enough support for him on the Cardinals defense.

San Fransisco 49ers

2014 Rankings: 4, 6, 15

Strong safety Antoine Bethea was a Pro Bowler and Chris Culliver was the fifth best cornerback in a supporting role by adjusted success rate, according to FBO.

2015 Projected Pass Defense Ranking: Bottom Ten

The 49ers had arguably the worst off-season of any team. They parted ways with their great head coach Jim Harbaugh, and lost five time first-team All-Pro linebacker Patrick Willis to retirement. Promising rookie linebacker Chris Borland also shocked the team with an early retirement. The 49ers defense also lost two good cornerbacks, the aforementioned Culliver (to the Redskins) and cornerback Perrish Cox (to the Titans). It doesn't end there, the 49ers then lost two great pass rushers: oft troubled Aldon Smith (who was released recently) and Justin Smith to retirement.

The 49ers signed cornerback Shareece Wright (Chargers), linebacker Phillip Wheeler (Dolphins), and used their second round pick used on Samford safety Jaquiski Tartt. The 49ers pass defense will really struggle this season.

St. Louis Rams

2014 Rankings: 20, 10, 25

Janoris Jenkins and rookie E.J. Gaines proved to be a good cornerback duo last season. Gaines was the ninth best cornerback in a leading role, according to FBO, but the rest of the secondary were too young and not yet ready to take the next step.

2015 Projected Pass Defense Ranking: Top Ten

The Rams were set to return all 11 of their defensive starters from last season until E.J. Gaines suffered a season ending injury during week 1 of preseason. However, having 10 returning players and defensive coordinator Gregg Williams entering his second season should alleviate growing pains for the replacement and help bring this very young pass defense to top-ten status.

Seattle Seahawks

2014 Rankings: 3, 1, 1

Everyone knows about the Legion of Boom.

2015 Projected Pass Defense Ranking: Top Five

The Seahawks couldn’t pay everyone, so they cut ties with cornerback Byron Maxwell (to the Eagles). The Seahawks replaced him with cornerbacks Cary Williams (from the Eagles) and Will Blackmon (from the Jaguars), who will fit right in to a ready-made scheme alongside Richard Sherman and Earl Thomas.

NFC West Rushing Defense Rankings

Per DVOA and Fantasy Points Against Running Backs, per ESPN

Arizona Cardinals

2014 Ranking: 6, 4

The Cardinals overcame the torn ACL of defensive tackle Darnell Dockett to become a top ten rush defense. Defensive end Calais Campbell gave the team a Pro Bowl effort and nose tackle Dan Williams was the run stuffer the team needed.

2015 Projected Rush Defense Ranking: Top Ten

This offseason the Cardinals lost Williams (to the Raiders) and fellow defensive tackle Dockett (to the 49ers). The team shored up the defensive line this offseason using their second round pick on Missouri defensive end Markus Golden in the second round, who can play the run well. In free agency, the team signed defensive end LaMarr Woodley (from the Raiders), outside linebacker Sean Weatherspoon (from the Falcons), defensive end Cory Redding (from the Colts), and defensive tackle Corey Peters (from the Falcons). All of these signings will help keep this team a top-ten rush defense yet again.

San Fransisco 49ers

2014 Ranking: 10, 7

The defense was always good under the tenure of Harbaugh, but towards the end of the 2014 nfl season everything sputtered out of control.

2015 Projected Rush Defense Ranking: Bottom Ten

In free agency the 49ers signed defensive tackle Darnell Dockett (from the Cardinals), but lost defensive lineman Ray McDonald (to the Bears). With the 17^th pick they drafted defensive end Arik Armstead from Oregon, although he won’t be too much of a factor in his rookie year. The losses of Willis and Borland and the mass player turnover will prove costly.

St. Louis Rams

2014 Ranking: 4, 6

Arguably the best defensive line in football held their own last season.

2015 Projected Rush Defense Ranking: Top Five

The offseason saw the Rams make minimal moves. They lost defensive tackle Kendall Langford (to the Colts), but signed another very good defensive tackle Nick Fairley (from the Lions). Everyone else is returning to this team; look for reigning defensive rookie of the year Aaron Donald to really take off.

Seattle Seahawks

2014 Ranking: 2, 2

Although the Hawks didn’t have the greatest start, they finished really strong. Michael Bennett led the best defense in football with seven sacks.

2015 Projected Rush Defense Ranking: Top Five

The losses of defensive end O’Brien Schofield (to the Falcons) and linebacker Malcolm Smith (to the Raiders) will be forgotten quickly. The team brought in defensive tackle Ahyba Rubin, who was once a good run stuffer, and drafted Michigan defensive end Frank Clark in the second round.

NFL & Fantasy Football Chat Room

[iflychat_embed id="c-0" hide_user_list="yes" hide_popup_chat="no" height="400px"]