Bolton's defense has been bad this year, well worse than bad really, but suffice to say following Bolton so far this season has been a thankless task.
The club has been particular poor at the prevention of goals, something that I think springs from them giving up a rather large amount of shots. They have given up 70 shots so far this season in league play, an average of 14 shots per game. Of those 70 shots, the Bolton defense managed to block 12, meaning 58 shots have rocketed towards Adam Bogan's goal.
To get a better picture of what Bogdan has faced so far this season, consider the graphic below. It shows the location of shots fired passed the Bolton defense, the larger the circle the more shots in that area. The blue "X"s indicate goals scored during the run of play.
The first impression is that the vast majority of shots by Bolton's opponents that have been on frame have been low. In fact, 87.5% of opponent's shots on goal have been on target in the lower half of the goal. I'm not exactly sure why this is, to be honest, but it is an interesting pattern. Perhaps not surprisingly, 7 of the 8 run-of-play goals allowed by Bolton have also resulted from low shots. This however, does not mean that Bogdan is struggling to stop low shots as his save percentage on low shots (14/21 or 66.7%) is the same as it is on high shots (2/3 or 66.7%).
In fact, looking at these numbers, 66.7% save percentage is respectable for a starting keeper, it is clear that Bogdan should not be blamed as the main problem behind Bolton's goal allowed situation. The defense needs to surrender less shots overall or at least start blocking a higher percentage of the shots opponents are taking. Until this is remedied, or Bogdan starts putting up hockey goalie-esque save percentages, Bolton are going to continue to hemorrhage goals.