Enter the Block Zone: The Pinpoint Precision of a Blocked Field Goal

3D Block Zones

This is the first piece in a two part series on field goal blocking. The second installment focuses on outside kick-blocking strategy and can be found here

NFL kickers are supremely accurate and have continued to improve for years. In 2023, 85.9% of field goal attempts were successful, the second highest rate in NFL history, despite the fact that long kicks are being attempted more frequently than ever. Unlike the constant battle of adjustments between offenses and defenses, there seems to be little that opponents can do to slow the one-sided trend of increasing accuracy. The best defense against a kicker is to simply keep the ball outside of their (ever increasing) range.

There is one defense I’ve neglected to mention: the FG block. However, blocked field goals are exceedingly rare. Per nflfastR play-by-play data, there were just 19 blocked field goals and 8 blocked extra points in 2023. That’s fewer than one total block per team. Blocked kicks are also exceedingly valuable, especially given the high field goal percentages in today’s game. A blocked FG often saves the defense >2.5 points in expectation, while occasional blocks are also returned for touchdowns. In this two-part series, I’d like to explore what makes blocking a field goal so difficult, how some kicks are blocked and how teams can potentially maximize their chances to accomplish this (near) impossible task.

All blocked kicks accomplish the same task (preventing a field goal or extra point attempt) but many do so in different ways. For our purposes, blocks can be classified into 4 main categories:

1. Interior Block
2. Outside Block
3. Second Outside Block
4. Jumped Center Block

The first two categories are fairly intuitive. An interior block refers to a kick blocked by a defender on the inside of the defensive line, typically a defensive tackle or end. Outside blocks are field goals deflected by a speedy defender that bends the edge and leaps in front of the kick. These two groups will be the focus of this series.

A “second outside” block refers to a specific play that I noticed when charting blocked field goals. It refers to when an end-man on the line of scrimmage for the kicking team engages the outside rusher and the second outside rusher is left unblocked, as in this play. This occurred in 6 of 55 charted blocks and seems like a blocking breakdown. Last is the most iconic play, the jumped center block. The best analysis of this rare bird is simply to be Myles Garrett.

Focusing on the first two categories of blocked kicks, it’s clear that they’re two kettles of fish, with very different challenges. The primary obstacle of an outside rusher is time. When the field goal operation is seamless, even the twitchiest outside rusher has little chance to reach the kick in time. As a result, many kicking teams choose to lightly chip or not block the outside rusher at all. On the other hand, while time is also a factor, the key challenge for an interior kick blocker is positioning. What is the optimal position to block a field goal? Enter the block zone…

Block Zone Methodology

What is the block zone? Simply put, the block zone is the area through which the kicked football is overwhelmingly likely to travel on its way towards the uprights. Think of it like baseball’s strike zone at a given distance from the kick point. The block zone is not set in stone and can vary slightly based on a multitude of factors, including kick distance, kick speed and weather. This post will be focusing on the typical block zones for 35+ yard made field goals (prime candidates for a blocked kick) at 5, 6 and 7 yards from the kick point.

The upper and lower boundaries of the block zone can be computed using trigonometry…

Theoretical Field Goal Kick Height

In this case, we will solve for the side opposite to the kick angle (the kick’s height) for a given distance from the kick point. Of course, it is impossible to know the precise angle that the kick will travel at. In a previous post I used SNF Kicks tracking data to estimate kick angles for ~40 tracked field goals. In that dataset, the mean kick angle was ~33° with a standard deviation of 3.31°. Assuming a normal distribution of kick angles, we would expect approximately the central 50% of kicks to range from 31° and 36°, 75% from 30° to 37° and 90% from 28° to 39°. Using these ranges one can estimate the top and bottom of the block zone with the following equation:

Kick Height = tan(Kick Angle) * Distance From Kick Point * Drag Adjustment

After experimenting with my kick trajectory calculator, I chose to use the simple drag adjustments of 0.96 for 5 yards from the kick point, 0.95 for 6 yards and 0.94 for 7 yards. That’s all you need to estimate FG height! For example, a 30° kick at 5 yards from the kick point should reach a height of approximately tan(30°) * 5 * 0.96 = 2.77 yards, or 8.31 feet off the ground. This calculation is not exact, as the drag adjustment can be affected by factors including air density and the kick’s exact velocity. However for most weather conditions, altitudes and typical kick velocities (65–75 mph), it should be fairly precise (+/- ~0.25 feet).

Determining the horizontal bounds of the block zone is even simpler, thanks to the wealth of tracking data that the NFL has made publicly available for its annual Big Data Bowl. This includes the position and velocity of the football on the field in two dimensions at 0.1 second intervals. Using this data, I found the horizontal position of the football on made 35+ yard field goals at 5, 6 and 7 yards (+/- 0.5 yards) from the kick point. These positions were then compared with the expected “midpoint” of each kick at that distance. Think of the midpoint as a straight line drawn from the kick point to the center of the uprights. The resulting ball locations relative to the midpoint were used to create 50%, 75% and 90% block zone boundaries. For instance, the 90% side-to-side boundary of the block zone at 6 yards from the kick point ranges from -1.45 to 1.40 feet. This means that on around 90% of made 35+ yard field goals, the football (more precisely, its tracking chip) passed within a 2.85 foot range of the midpoint.

Block Zones Visualized

Now that it’s clear how to compute them, here’s a look at sample block zones 6 yards from the kick point…

Block Zone 6 Feet from Kick-Point (To Scale). Red Line Marks 10.5 Feet High

The first thing that jumps off the page is just how small the block zones are. At 6 feet from the kick point, a portion of the football in 50% of successful 35+ yard field goals is expected to pass through a region 2.1 feet tall and just over 1.25 feet wide. The more inclusive 75% and 90% block zones are larger, but still relatively thin horizontally. This may initially seem surprising, but kicking a football is an extremely precise action. Most made field goals are kicked near the center of the uprights and at 6 yards from the kick point the football has generally completed <20% of its journey towards the goalposts. As a result, the trajectory of made field goals should logically be restricted to a small horizontal area. However, this predictability does not make blocking a field goal simple. If we assume that the upper limit of an interior blocker’s leaping reach is ~10.5 feet (the red line in the plot), then it becomes clear what the major impediment for interior blockers is. Even with 2 yards of penetration, most kicks should fly above the kick blocker’s outstretched arm. One final thing to notice is that the block zones are shifted slightly left of the midpoint. This seems to be because the average kicker has a slight tendency to hook their made kicks, rather than fade them.

A two-dimensional representation of a block zone is useful, but comparing block zones requires three dimensions. Here’s what all 3 block zones at 5, 6 and 7 yards from the kick point look like…

3D Block Zones (Measurements in Feet). Horizontal Lines at 10.5 Feet

These 3D block zones can be visualized and manipulated within the “Block Zones” tab of this Shiny app. Immediately apparent from the 3D block zones is the importance of interior penetration. At 5 yards from the kick point, the vast majority of made 35+ yarders are below 10.5 feet and therefore generally reachable. In sharp contrast, the entire 90% block zone from 7 yards away is at or above the 10.5 foot threshold. Kick blockers need tremendous good fortune or inclement weather conditions to even have a chance to deflect a kick from that distance.

While distance from the kick point has a tremendous impact on the vertical location of the block zones, the absolute differential in the width of the block zones is far milder. For instance, the 75% block zone at 5 yards away is ~1.7 feet wide, while from 7 yards it spans approximately 2.4 feet (to clarify, the width of the block zone refers to the area through which the football’s tracker passes through, not any part of the ball). This implies that interior rushers can largely target a single horizontal position and fight to get as close to the kick point as possible in that location.

Interior Block Timing

Block zones represent the area through which the football is likely to pass on a made field goal. But blocking a kick is not simply about positioning. There is a temporal element as well. An interior kick blocker with his hand in the block zone just 0.5 seconds after the kick is powerless to deflect it. So, when is the correct moment to leap?

There are two key benchmarks for an interior rusher to time against, the snap of the ball and the time of kick contact. Per both Big Data Bowl tracking data and my manual timing (of approximately 50 kicks), the average time from the snapper’s first movement to kick contact is ~1.5 seconds with a typical range of 1.35–1.6 seconds. Timing the location of the ball at a specific distance is impossible to do manually, but thankfully can be done with tracking data. As the ball tracking data is in 0.1 second increments, the exact ball locations are a bit noisy, but they suggest that the typical kick reaches 5 yards ~0.27 seconds after kick contact, 6 yards at ~0.31 seconds and 7 yards at ~0.37 seconds. This is a bit longer than the ~0.2 seconds that it would be expected to take to travel 5 yards at typical 24–27 yds/second ball speeds, perhaps due to noisy or imprecise ball location tracking data.

Taking this information into account, it seems appropriate for an interior kick blocker to practice timing their maximum vertical reach for ~1.8 seconds after ball snap or more precisely 0.3 seconds after kick contact. This timing mechanism should work relatively well for the entire range of reasonable block zones.

Conclusion

Blocking a field goal is one of the most difficult feats in professional sports. It requires precise timing, athleticism and accurate positioning to even have a chance to deflect a kick. Perfecting such a difficult craft requires careful and diligent practice. Block zones aren’t just an abstract concept. They can be used as real, physical practice tools or to objectively evaluate interior kick blockers beyond the rare actual deflected kick. NFL Kickers are so accurate that they telegraph where a made kick will be. Knowing the goal is 90% of doing the impossible.

Thanks to the NFL for openly providing (2022) Big Data Bowl tracking data for special teams plays. More of my work can be found here on Medium, at Down on The Farm and on Twitter @matan_writes.