Requiring three neutral jokers to touch the ball before a goal counted raised RPE 8% and time pressure 13% while distance per minute fell 7%. The pitch also doubled in size, so a matched retest has to separate the rule’s demand from the extra space.

The finding comes from a pilot study by García-Calvo and colleagues in the International Journal of Environmental Research and Public Health. It compared two ten-minute possession games played in counterbalanced order, so neither version always came first. ¹

Five passes earned a goal in both games. The restricted version counted a goal only when at least three jokers — neutral players who join whichever team has the ball — had participated in the sequence.

The format was listed as 6+2 against 6+2, with jokers in lateral areas and no direct passes between jokers. Players therefore had to preserve possession, monitor which jokers had received and find the remaining participant before the fifth pass completed the score.

Tracking joker involvement while reading teammates and pressure could explain the higher ratings, but the researchers did not measure attention, working memory or scanning. The rule’s cognitive mechanism remains a plausible interpretation rather than a demonstrated cause.

The reported result

RPE rose from 5.95 to 6.43 and time pressure from 56.00 to 61.88 in the restricted possession game. Distance per minute dropped from 104.10 to 96.58 metres.

RPE, peak heart rate, distance per minute and time pressure carry the strongest conventional statistical support. Mental effort and perceived fatigue rose in the descriptive data, but their stronger labels came from magnitude-based inference, a method that grades an effect by its size rather than by a hypothesis test, and not from significant paired tests.

The pilot also ran the same comparison in a second format, games with goalkeepers and regular goals. There the participation rule produced no significant differences in RPE, distance per minute or the mental-demand measures, which makes the game objective part of the result rather than a minor detail.

Why the pilot needs retesting

The published task table lists the unrestricted possession area as 40 by 20 metres and the restricted area as 40 by 40 metres. If accurate, the available area doubled alongside the scoring rule, so the comparison cannot isolate the effect of tracking three jokers.

The article begins with 40 players and later reports eight exclusions without stating the final analytic sample cleanly. Its mean-speed row also repeats the RPE values despite a simultaneous fall in distance per minute, so that row should not guide a session decision.

Players reported greater demand while covering fewer metres per minute, but the publication does not establish how much came from the participation condition, the reported area change, more passing errors or reduced ball-in-play time. The authors themselves identified effective playing time and pre-task mental fatigue as missing measures.

A low distance total therefore says only that players covered less ground. It cannot show whether they made more passing decisions, completed the intended circulation, lost effective practice time or experienced greater pressure while trying to satisfy the rule.

Add passing outcomes to the load record

Clemente and colleagues’ systematic review and meta-analysis pooled six crossover studies involving 75 players and found no significant effect of pre-game mental fatigue on total running distance. Four studies involving 46 players also produced no significant pooled tactical effect, with high heterogeneity. ²

The review covered youth and young adult male players who completed fatigue-inducing tasks before small-sided games. It does not test fatigue generated by a pass rule during play, but it shows why unchanged distance cannot establish an unchanged cognitive state.

Nine under-19 outfield players in Trecroci and colleagues’ crossover study completed a Stroop task, a fast colour-word test used to induce mental fatigue, or watched a documentary before two small-sided games. The fatigue condition produced likely lower passing accuracy, shot accuracy, passing and dribbling decision scores, and acceleration distance per minute. ³

Those findings do not prove that the three-joker condition damaged passing. They identify the actions that should be recorded when players report greater mental demand, because technical and decision outcomes may change without a matching shift in total distance.

Count five-pass scores, sequences involving three jokers, turnovers before the third joker receives and seconds required to reach the third joker. Time how long the ball remains in play, because lower distance per scheduled minute may reflect stoppages and failed sequences rather than slower movement during active play.

Retest the rule in matched bouts

Use the same area, player numbers, joker positions, bout length, scoring target, ball supply and coach behaviour in both conditions. Alternate the order, place the comparison on the same microcycle day and collect a pre-bout mental-fatigue rating before players start.

Record distance per minute, high-speed running, accelerations and decelerations from GPS. Ask each player immediately afterwards for RPE, time pressure and mental fatigue on the same short scales used in every exposure.

Three matched exposures offer a better minimum than one comparison. A professional-player study of how much the same drill varies from session to session found coefficients of variation of 2.2% to 4.6% for distance per minute, compared with 12.2% to 29.4% for high-speed running and 9.4% to 22.5% for mechanical work. ⁴

Those ranges are not universal cut-offs for another squad. They show why one high-speed or acceleration result should not decide whether the participation rule altered the physical dose, while a repeated direction across matched sessions is more persuasive.

A systematic review of small-sided-game variability reached the same broad measurement conclusion. Internal and low-speed external measures tended to vary less than technical execution and high-speed output, so passing outcomes and high-intensity actions need repeated observations. ⁵

Decide from three records

Valid sequences show whether players learned the requested circulation. GPS shows how they moved, while RPE, time pressure and mental-fatigue ratings show how the bout felt to the players performing it.

The decision depends on the intended football action. A coach seeking wider circulation should require more successful use of lateral jokers, while a coach seeking patience under pressure may accept longer sequences only if turnovers and dead time do not consume the bout.

Replacing possession scoring with mini-goals changed total distance, speed zones, accelerations, heart-rate exposure and RPE in a repeated study of 16 amateur players. The researchers kept the 30-by-20-metre area constant, although the mini-goal condition also required every teammate to cross halfway before scoring. ⁶

Changing both the goal target and halfway-line requirement means that study cannot isolate either rule as the cause. It still demonstrates that another configuration produced different running demands, so the three-joker pilot cannot support a general claim that added instructions leave GPS output unchanged.

A dataset posted to Figshare in June 2026 tested graded instruction loads on 24 male under-14 players in small-sided games. In its published description, only the highest instruction load increased distance and high-intensity actions; lower loads left physical responses stable, while defensive organization dropped after the highest load. ⁷

The dataset contains downloadable player-level files, but the result here comes from its published description rather than a fresh calculation. An under-14 sample cannot settle the senior game, though the dose pattern warns against assuming that every added instruction has the same physical effect.

A professional-club study covering 279 individual drill observations also found large drill differences in distance, high-speed running, accelerations, decelerations and RPE. Because formats varied in area, numbers and objectives, it supports paired GNSS and RPE monitoring without isolating a three-joker rule. ⁸

After the third matched exposure, place valid five-pass scores, third-joker time, ball-in-play seconds, distance per minute and player ratings on one sheet. If ratings rise but three-joker completions do not, reduce the required joker count or remove the condition.