score:2
Yes, they use different algorithms.
Bing made the switch to use Kayak back in 2011, and their partnership meant that:
Bing Travel flights has retained its βlook and feel,β but with the exception of Bingβs Price Predictor, the tools and filters basically are the same.
Recently, Kayak produced its own new price forecaster, and if you'd like to read more about how that works, they have an article on their site: KAYAK Launches Price Forecasts For Flights.
But yes, long story short - different forecasting algorithms, and pretty much the same flights.