Based on the worst-case scenario (WCS) perspective, we investigated whether the decrease in match running ability of professional Footballers affected their technical performance. 8 match running performances and 21 technical performance data were collected from 275 players throughout the 2018 CFL season via the STATS Pro?誖 computerized video tracking system. Using the peak period (Peak-5min) of high-intensity running distance (v>5.5m·s-1) within 5 minutes as worst-case scenario, and considering three game situations of match place, team strength and opponent strength, we created a generalized mixed linear model, and employed magnitude-base inference to define the effect of reduced running ability on technical performance. The results show: (1) In the WCS identification, high-intensity running distance in the rolling period Peak-5min was 11.9% greater than that in the fixed period (ES=0.41, 99%CI[0.4,0.43]), and high-intensity running distance in the Post-5min declined 22.8% compared with that in the fixed period (ES=0.58, 99%CI[0.55,0.61]). (2) After the peak period, there was a clear downward trend in the players' running ability, which was characterized by a reduction in the distance and frequency of running, as well as a decline in the average duration and average running speed. (3) Frequency of the technical executions of the players (passes, individual possessions, touches per possession, runnings with ball, shots, etc.) decreased with the decline of the running ability (ES=0.26~0.63), and the technical ability in running (the running speed when possessing the ball and catching the ball, and the average speed when running with ball) obviously declined (ES = 0.36~0.68), but the quality of the technical executions (short pass accuracy, forward pass accuracy, duels won, Successful clearances, etc.) did not decrease. Studies have shown that when professional footballers' running ability temporarily decreases, the number of technical performance completions is reduced according to subconscious strategies to ensure that the quality of technical performance is maintained at a relatively stable level. |