Among others, a positive development could be boosted by more playing time, playing time on a higher level or better performances on the pitch.
A negative development could be due to the player being active on a lower level than he used to play, bad performances or the fact that he does not play that often as he used to do.
A SciSkill Development of 0.0 could indicate that a player is performing exactly like our algorithm expects him to do. Another reason could be inactivity (e.g. a long-term injury or suspension).