Question Number: 34220

Law 2 - The Ball 5/16/2021

RE: Under 19

Jonathan of Philadelphia, Pennsylvania Unites States asks...

IFAB states ball pressure should be 8.9-15.6 PSI. However, I have never seen an actual concrete number that international matches shoot for. MLS Next youth in USA asks for 13 PSI and they are the only league I have seen give a concrete number given how officially sanctioned it is. What do most professional leagues shoot for? I would like to buy an automatic ball pump, but the non-hugely expensive ones only go up to 12, which is smack middle of range but would be technically insufficient for, say, that level of game.

Answer provided by Referee Richard Dawson

Hi Jonathan,
air pressure affects how far a kicked soccer ball could travel and what level of control you might have on its flight path or dribbling touches. I suggest it would be great science for a team, or family project, to test this principle!

When a ball is pumped to the max, it will be hard, so more of the energy from a kick is moved into the ball, whereas a miminmum inflated softer ball, when kicked, will lose more energy as the force is absorbed into the deforming of the ball's surface.

The issue with hard is it HURTS if you are struck by that ball or if you kick it poorly. I watched as a very good player, who shall remain nameless, was demonstrating kicking techniques using his barefoot to strike balls with amazing results, trajectory, and speed. Although his foot was beet red after the impact, he was always making a point to explain how important it was to strike the ball correctly. He had a slight slip and took a kick where the 15 lb rock ball broke his toes rather painfully.

Sigh even those who know how, do not always know better lol

I was assisting at an international coaching seminar where they were on about the skill and technique on free-kicks and heading. In this instance, it was a corner kick being taken by a VERY good player who understood that on this cross, the ball was not to be lobbed into the box. It was to be shotgun powered to be hit through the PA with a very low curve arc. The ball was maxed inflated s0 when I went up to head the ball it banged off my head so hard I saw stars and damn near blacked out it was such a powerful impact even if I had snapped the old back and neck into it. It ricocheted like a rocket off my noggin, leaving no doubt as to the effectiveness of a fast hard incoming ball being redirected into the goal leaves a keeper scant chance to react.

As a rule of thumb, I tend to go lower scale 9 lbs at youth ball size 3 or 4 and 12 to 13 for adult ball size 5. Some referees bounce the ball to test the ball or squeeze along the sides making a small impression with the fingertips provided it is not over-inflated. Rather than use spit, I usually pinch/rub my nose on each side with a thumb and forefinger to extract the nose grease to ensure good straight needle entry when using a pump or gauge. My colleagues did note, given the crazy times we live in with Covid 19, that advocating "nose grease" to referees for ball inflation might be frowned on. The protocols here now for referees are pretty strict with no handshakes, no AR flags to be provided, no touching corner flags, turning up already kitted out, social distancing, etc. If I am handed the game ball or balls by the team recorded with the league power to do so as the designated home team and I am certain they are legal I do not readjust based solely on the request of the opposition but do make certain if multiple balls are used they are all inflated the same! If both teams complain they are too hard I have no issues making them softer if that is their wish within the LOTG guideline!
Cheers

Answer provided by Referee Joe McHugh

Hi Jonathan
My advice is not to go for an automatic ball pump yet rather just buy a pressure gauge and use a small hand pump if needed.

The only time that I used the gauge was as a 4th official or in important games where the referee crew were given 5/6 balls before kick off or on a day when I felt like it would be a good idea and where the teams had provided balls before kick off in the changing room in a timely manner. I was always mindful that it was not my ball and that I was extremely careful about the valve and any inflation that was required.

With the use of the gauge I quickly developed a "feel" for a properly inflated ball using a two thumb test which is what I would do on the field of play if players complained about ball pressure usually under inflated. From experience at Underage there was always concerns about the balls that were inflated high on the pressure scale as they felt hard on a kick. In general I felt that the 9psi was adequate at all levels and I took that as my benchmark using the thumb test.

At a recent new referee course one of participants recounted an experience as a coach where in a particular game both U12 teams were complaining about the ball being overly hard which was affecting their play. I would say it was probably a 15 psi inflation and while perfectly okay as per the IFAB advice it was just too hard and affecting the game and the players enjoyment. The referee would not accede to a ball change request and while perfectly entitled to do so he showed no empathy for the players and what they were experiencing or used to. Kicking a rock hard ball or getting struck with such a ball is not very pleasant at any age never mind U12s