```ruby
require 'active_support/concern'

module PadawanRun
  extend ActiveSupport::Concern

  included do
    def improvements_towards(better_run)
      improvements = {time_differences: [], missed_splits: []}

      return improvements if category != better_run.category
      return improvements if splits.size != better_run.splits.size

      reduced_splits.each.with_index do |split, i|
        if better_run.reduced_splits[i][:duration] < split[:duration] && !split[:reduced?]
          improvements[:time_differences] << {split: split, time_difference: (split[:duration] - better_run.splits[i][:duration]).floor}
        elsif split[:reduced?]
          improvements[:missed_splits] << {split: split}
        end
      end
      improvements
    end
  end
end
```

Fix a 500 on comparison pages for runs with missed splits
user
```ruby
require 'active_support/concern'

module PadawanRun
  extend ActiveSupport::Concern

  included do
    def improvements_towards(better_run)
      improvements = {time_differences: [], missed_splits: []}

      return improvements if category != better_run.category
      return improvements if reduced_splits.size != better_run.reduced_splits.size

      reduced_splits.each.with_index do |split, i|
        if better_run.splits[i][:duration] < split[:duration] && !split[:reduced?]
          improvements[:time_differences] << {split: split, time_difference: (split[:duration] - better_run.splits[i][:duration]).floor}
        elsif split[:reduced?]
          improvements[:missed_splits] << {split: split}
        end
      end
      improvements
    end
  end
end
```
assistant