Birdie Bogey is a ratio of birdies to bogeys, that is how many bogeys are scored for every birdie that is scored. The statistic is reported like this:
1:1.2
Where the 1 to the left of the : is for birdies and the 1.2 to the right of the : is for bogeys. In this example for every 1 birdie that is scored, 1.2 bogeys are scored.
In Golf Stat Lab any hole with a score less than par counts toward the birdie side of this ratio (birdies and eagles) while any score over par is counted toward the bogey side of this ratio (bogeys and double bogeys, etc.).
Birdies are always represented by a value of 1 in this statistic, so good performance is indicated by having the bogey side of the ratio (1.2 in our example) as low as possible. A ratio of 1:0 would mean that no bogeys we're scored and indicates good performance. A value of 0 (no ratio, just a single digit) indicates that no birdys were scored and indicates poor performance.
Birdie Bogey can be found on the Scores Report.