Manchester City are the top scorers in the Premier League this season but the reigning champions find themselves all but out of the title race. Four defeats in 16 games have left them 14 points adrift of leaders Liverpool. Their defensive record has undermined them. Pep Guardiola has always built his success on defensive excellence. Endless possession coupled with a relentless ability to sustain attacks and snuff out counters. It was a concern during his first season with Manchester City but he perfected the balance in his second. Kyle Walker pointed out on Saturday all he had ever known since joining the club in the summer of 2017 was success and it was easy to appreciate his point. It was not just the trophies but the manner in which they had been won. City conceded only 23 Premier League goals last season, just 27 the season before, and it owed little to luck. Guardiola: City cannot compete with the elitePremier League table | Fixtures | Top scorersOpta’s expected-goals models indicates Manchester City had the best defence last season, the season before and even, perhaps surprisingly, the season before that. Guardiola’s first campaign was a challenge at times when they were…