Uncoached: How to defend as a Scrum-Half

June 20, 2023

Defending while playing scrum half is one of the least defined roles on a rugby field. In attack, the 9s role is very structured; they pass the ball from the ruck and run or kick sometimes. The variation is obvious from how the different teams in the Six Nations use their scrum half in defense.
Ireland, England, and Italy use their scrum-half as a sweeper about 3-5 meters behind the main line most of the time. When in their 22 those teams move their scrum-half out to the wing.
Wales used Thomas Williams as a bonus inside center. Williams is big and strong for a scrum half and his main defensive weakness is defending in space. So, by using him as a bonus center they have put him in a position where he won’t be exposed and plays to his size and strength.
Scotland used their scrum-halves Ali Price, Ben White or George Horne as a shooter to cut off a team’s second pod preventing the other team from moving the ball wide. Again, this plays nicely into the strengths of their 9s who are not very big but are very fast, especially over a short distance and are competent tacklers. So they can get off the line quickly to get in the eye line of the opposition decision-makers and hit them should they make the wrong decision.
France uses Antonie Dupont as a free roamer who splits time between the backfield and main line. Depending on field position and what the other teams are set to do. If the other team is going through phases around midfield Dupont can be found just behind or around the fringe of the ruck. If the other team is set to kick he drops into the backfield to be involved in the kicking duel or the counter-attack.
There is some variation in the southern hemisphere as well. South Africa has the most aggressive variation using Faf De Klerk as a free safety with a license to terrorize the other team’s decision-makers.
New Zealand’s two main 9s are weird; they defend similarly on a tactical level but their defensive skill sets are very different. Both Aron Smith and TJ Perenara defend as sweepers just behind the ruck. Smith usually stays there, only occasionally filling in around the ruck. Perenara likes to go into the front line more often and frequently wins turnovers at the ruck. Perenara is by far the most interesting defensively, but that’s an analysis for another day.
One of the main areas of the game is the scrum, what the scrum-half is doing at the scrum is up to them. There are two basic ways to defend Scrums: either stay up near the opposing 9 and apply pressure or drop behind your 8-man and defend space.
No one way is better than the other and how the scrum-half defends depends on field position or personal preference. For example, on a defensive scrum inside the opposing 22, the scrum-half can stay up marking the opposing scrum-half because it’s likely they are going to kick. Staying on the scrum-half allows there to be pressure on the passer and the kicker. In that situation, there is nothing to lose by defending aggressively because the other team is at a territorial disadvantage so you can afford to give away a few meters.
The problem with defending aggressively is if the scrum-half goes to the other side of the scrum where you aren’t. You’re stuck praying that the flanker breaks from the scrum quickly to make the tackle or the defense on the other side can cope with the extra man.
This is why I prefer to drop to the back of the scrum and defend zonally. You are not going to look stupid by being on the wrong side of the scrum; it also gives you more ability to affect the game.
Anything around the scrum is the responsibility of the scrum-half and the loose forwards. If the loose forwards make the tackle they are usually tackling low as a result there is a very clean target at the ruck and a turnover chance for the scrum-half or the 8-man.
A turnover is the best possible outcome from a completed scrum and because of that most teams are going to play their first phase wider from the ruck. So the scrum-half covers the inside of the 1st defender on whichever side the ball goes. If the tackle happens in midfield usually take the guard position on the blindside of that first ruck. This is usually pretty safe because teams rarely come back to the blindside after that initial carry and will usually attack the openside. If the ball ends up wider than the posts, typically the inside backs fill in and get as many forwards inside of where I am lined up. That way I am defending in midfield or as the widest defender. Then on the 3rd phase from the scrum, I’ll go back to the normal scrum-half position just behind the main defensive line.
Lineouts are much simpler in terms of defensive options. Many professional teams have their scrum-half defending at the front of the lineout. That is potentially a problem when defending trick plays to the front, scrum-half vs forward is always a matchup favorable to the attack. Since most lineouts in college rugby are to the front, I defend at the receiver position behind the lineout. Firstly, to prevent mismatches, and secondly to clean up loose balls or turnover from the lineout. Once the lineout is over it’s a simple track across as a sweeper behind the main line.
So that’s set pieces covered, however, most of the game occurs in open play or phase play. In phase play, most scrum-halves defend as a sweeper behind the mainline. After a tackle, the scrum-half lines up a few meters behind the ruck in case the ball is turned over so they are there to pass it away. The other reason the scrum-half is there is to organize the defense. It’s their job to make sure there are no gaps in the defensive line and to move the forwards around to fill the line appropriately making sure that the team is “numbered up” with the opponent on either side of the ruck.
Most of the communication a scrum-half does is with the forwards. Telling them to fold around the ruck, get tighter or spread out. It’s important to keep any directions as short as possible you have about 2-5 seconds to set the defense for the next phase. Since you have such little time to make adjustments you can’t afford to waste words.
Sometimes, if your teammates cannot get into position, you’ll have to fill in the gap yourself. Filling gaps sounds easy but it’s always a challenge because as scrum-half you are filling in at a variety of positions. You could be anywhere from the guard position to 5 out from the ruck. This means that you are defending in a variety of situations and making different tackles depending on your opponents and where you are defending.
As a sweeper, part of our role is easier: just follow the ball across the line and clean up short-range kicks or tackle players who have broken through the line. Tackling as a sweeper is pretty easy most of the time except when forwards poke their heads through the line and have someone hanging off of their legs. In that case, aim for a higher tackle to target the ball while bringing them down. Occasionally, you may encounter a forward breaking in open space, and in that scenario, it’s best to aim low and pray.
The more challenging tackles are the ones on the edge where you must quickly cover ground to neutralize a 2v1 or convert a 3v1 into a 3v2, basically overlap mitigation. That is typically thankless work because if you get to the edge late there is nothing you can do that will kill the overlap. The key is to beat or tie the ball to the edge so you stay in line with or ahead of the ball when sprinting to the touchline.
Usually, the only players a scrum-half gets to boss around on the pitch are the forwards. However, once a scrum-half progresses to higher levels of play where the ball can be spread from side to more reliably and kicking becomes more prominent, scrum-halves also work with the back 3. As Scrum-halves, we are typically working with forwards when the ball is getting wider and the winger is starting to think about coming into the line. Most of the communication is whether they are coming up or staying back. From there we just do the opposite, if they are coming up, we cover their position; if they are staying back we become the widest defender.
At the end of the day, these are just basic rules to follow. The system your team uses to defend, your strengths as a player and your teammate’s strengths dictate how you defend as a scrum-half.

Alexander MacDonald:
Journalism student at Arizona State’s Cronkite School, 3rd-year scrum-half and social manager for ASU Rugby.