Other sabermetricians have developed their own formulas using Smyth's general form, mainly by tinkering with the B factor.
Doing this would result in a run estimate for an entire team that puts out the individual's statistics.
Base runs, on the other hand, can be applied to any sample at any level of baseball (provided it is possible to calculate the B multiplier), because it models the way the game of baseball operates, and not just for a 162-game season at the highest professional level.
This means that base runs can be applied to high school or even little league statistics.
Some examples of shortcomings: One avenue for possible improvement in the model is the scoring rate estimator B/(B + C).