Wet weather in the following two years affected playing conditions, making the cricket pitches slow-paced and difficult to bat on. With little experience of such conditions, MacLaren had a succession of failures. His technique, based at the time on playing forward at the ball, was unsuited to wet pitches and it was only late in 1889 that he made the required technical adjustments and learned to play off the back foot (i.e. stepping backwards to play a shot). During 1890, his final year at Harrow, he captained the team and had his most successful season, scoring over 500 runs at an average of 42.54. In the match against Eton at Lord's, MacLaren once more succeeded when others struggled, and he scored 76 on a difficult pitch. In his four years at Harrow, MacLaren was twice awarded the prize for the school's best batsman, and received awards for his fielding. MacLaren also played football successfully: he captained his House team and played in the school first eleven in 1888 and 1889 before a knee injury forced him to miss the 1890 season. Unlike many of his fellow amateur cricketers in this period, MacLaren did not attend Oxford or Cambridge Universities, where he would have played a high level of cricket; his father could not afford to send him or his brothers there. On leaving Harrow, MacLaren found employment with the Manchester and Liverpool District Bank.