The red zone is a gold-mine for fantasy scoring. Of the 72 offensive touchdowns scored in Week 4, 55 of them (76%) came from within the 20-yard line, bringing the season total to 212 of 281 (75%).

We're a quarter of the way through the fantasy football season, and it should already be clear just how valuable touchdowns are. There are three running backs with five-plus touchdowns on the year, and they are also the top-three fantasy scorers at the position. Meanwhile, the only wideout with five touchdowns ranks second in fantasy scoring.

Touchdowns are also one of the most volatile stats on a week-by-week basis, but by taking a look under the surface and identifying players that are getting the ball in the red zone, we can identify players that have the highest probability of reaching the end zone. This can give us an idea of whose fantasy success is likely to continue, while also identifying players that are scoring at unsustainably high rates and may make for good sell-high candidates. It can also help us identify which players are scoring at low rates and which are likely to improve, making it worth considering trying to acquire them for cheap.

Let's get right to it.

New Opportunity Available in Minnesota

One of the biggest stories to come out of Week 4 was Dalvin Cook tearing his ACL. This obviously creates a huge void in the offense, which is especially true in the red zone.

Cook ranks seventh in the NFL with a 40.6% market share of the Minnesota Vikings' red zone opportunities (rushes and targets), and it also appears that the team's play-calling had shifted specifically to get him the ball in that range. The Vikes posted a 1.17-to-1 pass-to-run ratio inside the 20 last year, while their mark through four weeks in 2017 sits at 0.94-to-1. Not only is there a huge chunk of opportunities available without their lead back, but some of that volume will likely also be shifted over to the passing game. Combining that with Sam Bradford looking ready to return soon means there's room for a ton of increased fantasy value for Vikings pass-catchers.

Stefon Diggs has been scoring at an unsustainable rate in the red zone so far (three touchdowns on four targets), but with the extra opportunity available, it seems likely that his red zone volume will increase more than his touchdown numbers decreasing by much as we move forward.

Adam Thielen is tied with Diggs for the most red zone targets on the team, but he has yet to score a touchdown. Despite that, he ranks 22nd among wideouts in fantasy scoring, and the potential increase in red zone volume gives him a nice bump in upside.

Kyle Rudolph's 25 red zone targets led the Vikes in 2016 (good for a 32.9% market share) while nobody else saw more than 12. The volume hasn't been there for him this year, but he did see two of the team's eight red zone looks in the only game Bradford played. His 20% market share is likely to increase over the remainder of the season.

Concern for Leonard Fournette

Leonard Fournette was getting a ton of red zone work to start the season, which translated well to fantasy production. He finished as fantasy's RB3 in Week 1 and RB15 in Week 2 off the strength of scoring two touchdowns in that span. He has continued to produce well, finishing as RB12 in Week 3 and RB6 in Week 4 (with a touchdown in each of those games), but a sharp decline in his red zone workload makes that recent scoring a lot less encouraging moving forward.

His huge 44.4% share of the Jacksonville Jaguars' red zone opportunities between Weeks 1 and 2 was tied for the fourth-highest number in the NFL. That market share has cut in half over the past two games, though -- his 21.7% ranks only 44th in that time.

The Jags have also been increasingly pass-heavy in the red zone each week, culminating in a 3.0-to-1 pass-to-run ratio in Week 4. With Fournette's red zone work coming almost entirely on the ground (12 carries to 1 target), the rookie is unlikely to keep up the touchdown-per-game pace he has opened the season with.

Mike Gillislee's Sharp Decline

The New England Patriots are another team that has been getting significantly more pass-happy in the red zone. They had a 0.64-to-1 pass-to-run ratio through the first two weeks, but that has shifted significantly to 1.86-to-1 since Week 3.

Like Fournette, Mike Gillislee hasn't seen much passing work in the red zone, and this shift in play-calling has meant a huge drop in his share of the team's opportunities. He ranked top 10 in the NFL with a 37.1% market share in the first two weeks of the season, but that has plummeted to 15.0% over the past two games.

Averaging a pedestrian 3.4 yards per attempt on 14.3 carries per game, Gillislee's fantasy value relies heavily on touchdowns. While he still has a high ceiling on a weekly basis in the Patriots' explosive offense, his overall fantasy value is severely limited unless they get back to their run-heavy approach in scoring range.

Things Are Back to Normal for Zeke

Ezekiel Elliott didn't score a touchdown in his first two games, which was a real blow to his fantasy production. That lack of scoring wasn't a huge surprise when looking at his volume, though -- he accounted for only 22.2% of the Dallas Cowboys' red zone opportunities in those games (three carries and one target).

He has since seen a huge increase in volume, with his 61.5% market share of opportunities over the past two weeks being the highest in the NFL. That has also translated into a quick turnaround in his touchdown production, finding the end zone three times in those two games.

The Cowboys love feeding Elliott the ball -- he has 20-plus carries in three of his four games this year -- and after a slow start to the season, that heavy volume looks like it's going to continue holding up in the red zone.

Play-Calling Trends Worth Monitoring

The Arizona Cardinals remained incredibly pass-heavy in the red zone this past week, with seven pass plays to one run following an 11-to-1 mark in Week 3. They are one of three teams (joined by the Seattle Seahawks and Los Angeles Chargers) with pass-to-run ratios of at least 3.00-to-1 inside the 20.

The Chicago Bears (2.18-to-1), Oakland Raiders (2.11), Baltimore Ravens (2.10) and Miami Dolphins (2.00) make up the rest of the teams with a ratio above 2.00-to-1.

On the other end of the spectrum, six teams have a ratio below 0.80-to-1: the Pittsburgh Steelers (0.79), Indianapolis Colts (0.76), Carolina Panthers (0.72), Washington (0.72), Tennessee Titans (0.69) and Buffalo Bills (0.65).

Washington and Tennessee have been particularly run-heavy lately, too. Washington opened the year with six passes and no runs in the red zone in Week 1 before posting ratios of 0.38, 0.50 and 0.25 over the past three weeks, while the Titans opened the year with a 1.67 ratio before posting 0.44, 0.67, and a 0.00 mark in the weeks that followed.

The Detroit Lions have continued to be significantly more pass-heavy recently than they were to open the season. They posted ratios of 0.50 and 0.67 in Weeks 1 and 2, followed by 8.00 and 2.00 in Weeks 3 and 4. As outlined above, the Jaguars and Patriots have followed similar patterns.

Reflecting on Last Week's Trends

Dalvin Cook is a player I looked at with a lot of optimism in last week's Red Zone Report, and obviously with his season over, so is that optimism. Here's how the other players we looked at last week have fared:

Carlos Hyde continues to see significant volume. He accounted for 66.7% of the San Francisco 49ers' red zone opportunities in Week 4, and his 52.5% market share on the season continues to lead the NFL. He has only scored two touchdowns on his 21 red zone opportunities, but with a career 17.0% rushing touchdown rate and 18.8% receiving touchdown rate inside the 20, his volume should come with an increased touchdown total moving forward.

Kareem Hunt also continued to see big volume -- he received four of the Kansas City Chiefs' six carries inside the 20 -- bringing his market share of the team's carries to a league-leading 85.7%. Despite having only one target, his 44.8% market share of the team's opportunities is also still a top-five mark in the NFL.

T.Y. Hilton is hard to get excited about in the low-scoring Indianapolis Colts offense, and he didn't see a red zone target in Week 4. His 45.5% market share of red zone targets is still tops in the NFL, but that comes with very little overall volume, having seen only five targets while the Colts are one of the league's top-five most run-heavy offenses in the red zone. Unless we see a significant shift in play-calling, his big market share doesn't mean a whole lot.

After leading the Houston Texans backfield in red zone work to start the year, D'Onta Foreman saw only one red zone opportunity to Lamar Miller's six last week. Miller has now seen his share of the team's red zone work increase in two consecutive weeks (sitting at 42.9% in Week 4). With his overall edge in volume over Foreman, it looks like he's back to being the top back in scoring range, too.