Number 5 in Rugby: The Lock who Powers the Pack

The Number 5 in Rugby, often simply called the lock or the second row, stands at the heart of the forward engine. In the dance of rugby union, these players anchor the scrum, dominate lineouts, and provide the raw power and athleticism that drive a team forward. A well-rounded Number 5 in Rugby blends height, reach and strength with devastating work rate, tactical nous, and an ability to read the game. This article unpacks the role, responsibilities, skills, and evolution of the Number 5 in Rugby, offering a comprehensive guide for players, coaches, and fans who want to understand why this position remains one of the most influential on the field.

What is the Number 5 in Rugby?

The Number 5 in Rugby refers to one of the two locks in a standard rugby union forward pack. Wearing jersey numbers 4 and 5, these players form the “second row” in the scrum. The lock pair provide verticality and power in the scrum, help secure the ball in lineouts, and contribute significantly in rucks and mauls. In modern rugby, the Number 5 in Rugby is characterised not only by physical stature but also by mobility, ball-handling skills, and the ability to link play between the forwards and backs.

Beyond the lines and set-pieces, the Number 5 in Rugby operates as a catalyst for territory and tempo. A well-drilled lock can turn defensive set-pieces into attacking opportunities, control the pace of the game, and physically dominate opposition packs. In short, the Number 5 in Rugby is a cornerstone of any competitive forward pack.

The Physical Profile: Height, Weight, and Presence

Traditionally, locks are among the tallest players on the field. A typical Number 5 in Rugby might stand around 6ft 6in (about 2 metres) or taller, with a wingspan that allows them to contest lineouts and disrupt opposing throws. Weight varies, but many elite locks sit between 115kg and 125kg, with some exceed­ing that range depending on the build of the player and the demands of their team’s style.

But size alone does not define a Number 5 in Rugby. Modern locks combine the raw physicality with exceptional stamina and agility. They are expected to sprint to support runners, position themselves effectively in rucks, and maintain a high work-rate across the full 80 minutes. The ideal profile is a blend: tall enough to win lineouts, powerful enough in scrummaging, and mobile enough to cover the width of the field in defence and attack.

Key Responsibilities of the Number 5 in Rugby

In the heat of a match, a Number 5 in Rugby fulfils a diverse set of duties. These responsibilities can be grouped into core areas: scrummaging, lineouts, securing the ball at rucks and mauls, physical defence, and supporting ball-in-hand play.

Scrummaging: Providing the Core Power

The scrum is the anchor of the forward pack, and the Number 5 in Rugby is central to its stability. In the scrum, locks bind together in the second row, providing power through their hips, legs, and core. They push in unison with the front row, resisting opposing forces while maintaining a stable body height to control the scrum’s engagement and scrum-half feed. A proficient Number 5 understands timing, body angle, and how to absorb pressure, turning opposing packs at times into a compact unit rather than a collapsing wall of bodies.

Lineouts: The Jump, the Call, and the Catch

Lineouts are where the Number 5 in Rugby often makes a decisive impact. Locks are typically the primary jumpers or main targets in the air due to their height and reach. The responsibilities here include working with the lifters, calling the lineout strategy, and securing possession through accurate throws or reliable reception. A top-notch lineout throw from the number eight or hooker is complemented by a lock who can win cleanly at the highest point and set up quick ball for the backs or the attacking forwards.

Lineout height, timing, and the ability to read the opposition’s lo­cking targets are all essential components of the Number 5 in Rugby’s skill set. Psychological resilience matters too—the lock must stay calm under pressure, adjust calls mid-air if the throw is slightly off, and still secure possession under contest.

Rucks and Mauls: The Breakdown Specialist

In open play, the Number 5 in Rugby must be a relentless presence at the breakdown. They position themselves to secure clean ball after a tackle, compete for turnovers through clean jackals, and drive the maul when required. The lock’s tasks at the ruck centre on technique—hands in the right place, feet planted, hips square—and on stamina to sustain pressure as teammates recycle the ball. In mauls, the Number 5 in Rugby adds weight and drive, creating momentum that can push the team forward and wear down the opposition.

Defence and Physicality

Defensive duties for the Number 5 in Rugby are uncompromising. They are often required to anchor the second line and carry heavy workload in the contact zones. Their tackling technique must be sound, with a focus on shoulder contact, low hips, and wrapping to prevent offloads. A strong line speed, ability to read play, and communication with teammates ensure the lock contributes to a cohesive defensive unit. In addition, the Number 5 in Rugby frequently supports quick transitions from defence to attack—carrying the ball with purpose to gain hard metres and set up phase play.

Skills and Training for a Number 5 in Rugby

Developing into a reliable Number 5 in Rugby requires a well-rounded training regime that balances strength, power, endurance, and technical mastery. Here are the core areas to focus on:

• Power and explosiveness: Olympic lifts, plyometrics, and heavy squats to enhance scrum push and lineout take-off.
• Lineout technique: timing, lifting practice, and communication with jumpers and lifters; mastery of catch-and-drive tactics.
• Scrummaging technique: binding, body position, and engagement control to withstand pressure and push when required.
• Mobility and athleticism: sprint work, agility drills, and conditioning to cover the field in defence and support lines.
• Ball handling: catching, passing, and decision-making under pressure to link with backline plays.
• In-game awareness: studying opposition lineouts, defensive shapes, and scrum strategies to anticipate and react effectively.

Diet, recovery, and injury prevention are also critical. The Number 5 in Rugby endures high-impulse collisions, so a focus on robust joints, shoulder health, and proper sleep patterns supports longevity at the elite level.

Tactical Impact: How a Number 5 Influences the Game

While the backline often captures the flair in a match report, the Number 5 in Rugby can swing the momentum with a single lineout steal, a dominant scrum shove, or a timely maul. Their influence is felt in several tactical domains:

• Set-piece mastery: Dominant scrums generate pressure on the opposition and create gaining line opportunities for the ball carrier.
• Lineout supremacy: Winning your own ball while contesting the opponent’s throw increases territory and tempo control.
• Phase movement: A strong lock provides an essential link between the breakdown and the backline, enabling smoother distribution and more phases per possession.
• Defensive organisation: Locks often run a curved defensive line that denies space for the attacking threats of the opposition.
• Tempo control: By controlling how quickly the ball emerges from rucks and mauls, the Number 5 in Rugby can subtly influence the pace of the game.

Notable Number 5s in Rugby History

Across generations, certain players have defined the Number 5 in Rugby with legendary capability. Their leadership, technique, and influence on big-stage performances stand as benchmarks for aspiring locks. Notable examples include:

• Martin Johnson — England and British & Irish Lions: A towering figure whose leadership and set-piece excellence helped England reach global success in the 2000s.
• Victor Matfield — South Africa: Renowned for lineout mastery, game-reading intelligence, and a relentless work rate.
• Alun Wyn Jones — Wales and the British & Irish Lions: A perennial poster child for durability, lineout excellence, and leadership on and off the field.
• Brodie Retallick — New Zealand: A modern lock who combines athleticism with precision in set-pieces and breakdowns.
• Other influential locks have included the likes of Raphael Ibanez and Paul O’Connell, who shaped the role with their physical presence and strategic acumen.

The Evolution of the Position: From Heavy Pack to Modern Lock

The Number 5 in Rugby has undergone a notable evolution. In the amateur era, a lock’s game was dominated by physical power and set-piece proficiency. In the professional era, the role has expanded to require greater mobility, ball handling, and game management. Modern locks must be able to run lines, pick and go, and support the backline with unbroken consistency. This evolution mirrors the broader shift in rugby: less emphasis on the forwards’ brute force alone, more on the forwards as integrated components of a flexible, fast-moving unit.

Technological advances, sports science, and improved coaching methods mean that today’s Number 5 in Rugby often arrives at professional clubs with a more diverse skill set than ever before. They are expected not only to win lineouts and push the scrum but also to contribute to counter-rucking, defensive cover, and rapid ball retrieval. This makes the position both demanding and deeply rewarding for those who thrive in the forward pack’s cockpit.

How to Develop into a Number 5 in Rugby: Pathways and Coaching

For players aiming to become a Number 5 in Rugby, the pathway typically starts in youth development through grassroots clubs or schools, followed by progression into academies or professional development programmes. The early years focus on fundamental athleticism—jumping, sprinting, lifting, tackling—and a solid understanding of the game’s rules and set-pieces. As players mature, emphasis shifts toward technical refinement in lineouts, scrummaging technique, and decision-making under pressure.

Coaching for the Number 5 in Rugby should emphasise:

• Lineout drills that build timing and precision in both jumping and throwing;
• Scrum coaching that reinforces posture, binding, and sequence of engagement;
• Strength and conditioning programmes that target hip drive, core stability, and posterior chain strength;
• Mobility sessions to prevent injuries and improve reach and turnover of the ball;
• Video analysis to study lineouts, mauls, rucks, and opposition tendencies.

A successful development path also includes exposure to higher levels of competition, coaching with experienced forwards coaches, and opportunities to learn from seasoned Number 5 in Rugby players who model the blend of technique and leadership essential to the role.

Differentiating Across Leagues: Club, Premiership, Six Nations, Rugby World Cup

The requirements of the Number 5 in Rugby can vary slightly by competition. In domestic leagues, the emphasis may be on consistency in scrummaging and lineout reliability, as well as contributing to tight-phase play. At the international level, the pace, skill level, and strategic variety increase, demanding greater adaptability and leadership under pressure. In high-stakes tournaments like the Six Nations or the Rugby World Cup, the Number 5 in Rugby is not only a second-row anchor but a player who must read the game across multiple phases, anticipate opponent lineout calls, and provide leadership when the pace intensifies.

Clubs in professional leagues may prioritise workload management and player rotation, while international teams expect a higher peak performance, with players prepared to deliver in back-to-back fixtures against elite opposition. The best Number 5 in Rugby players, therefore, excel in this spectrum: they can perform at a high level week after week and adapt to the game’s tempo as required.

How to Read a Lineout: The Lock’s Throws and Calls

Lineouts are a battle of precision and timing. The Number 5 in Rugby, whether as a jumper or as part of the lift, plays a pivotal role in converting throw-in opportunities into clean possession. Reading lineout calls involves understanding the team’s pre-planned variations, recognising the opposition’s defensive alignment, and executing the throw with ideal speed and accuracy. The lock must also communicate with the thrower, the lifters, and the jumper to ensure a successful catch and secure ball for the team. Good decision-making at the lineout often translates into sustained pressure and improved attacking opportunities for the backs.

Common Misconceptions About the Number 5

There are a few myths that can obscure the true value of the Number 5 in Rugby. Some fans assume that all locks are merely “weight and height” specialists, neglecting the cognitive and technical aspects of the role. Others think that the lock’s primary function is to push in scrums without contributing elsewhere. In reality, the best Number 5 in Rugby are multi-faceted players who combine power with lineout excellence, breakdown skill, and leadership. They are as comfortable directing the pack from the front as they are supporting a backline move. Understanding the breadth of this position helps fans appreciate the complexity of forward play—where the hidden work often determines the winner of the game.

The Future of the Position: Trends and Innovations

As rugby continues to evolve, the Number 5 in Rugby is likely to become even more dynamic. Emerging trends include:

• Greater versatility: Locks who can play across the second row and blindside flanker roles, enabling more adaptable pack configurations.
• Enhanced athletic training: Data-driven conditioning to improve sprint capacity, ruck speed, and agility in tight spaces.
• Lineout diversity: Varied lineout calls, deceptive misdirections, and improved lineout algorithms that gain yards even under heavy contest.
• Increased emphasis on leadership: Captains and on-field organisers within the pack who balance aggression with strategy.

These developments will shape the next generation of Number 5 in Rugby players, making the role even more central to a team’s success.

Conclusion: The Unseen Engine of the Pack

The Number 5 in Rugby is more than a tall, powerful athlete wearing jersey number 5. It is a technical specialist, a tactical innovator, and a workhorse who sustains pressure across the match. From the lineout to the scrum, from the breakdown to defensive walls, the lock’s influence ripples through every phase of play. For clubs aiming to contend for honours or nations pursuing glory on the world stage, the Number 5 in Rugby embodies a blend of tradition and modernity—the backbone of any successful forward pack—and a critical determinant of how effectively a team can control the tempo of the game.

Whether you are a player aspiring to wear the Number 5 in Rugby jersey, a coach seeking to build a formidable second row, or a fan eager to understand the subtle mechanics behind elite rugby, the lock position offers a compelling blend of power, precision, and leadership. In the end, the Number 5 in Rugby is the engine that drives the pack, turning raw athleticism into strategic advantage and transforming potential into tangible success on the grand stage.