COLUMBIA, S.C.  (AP/WVOC) - Teacher seniority must be downplayed in layoff decisions during budget cuts under a bill advancing in the South Carolina Senate.

The measure, headed to the full Education Committee, would require school districts' "reduction-in-force" policies to consider teachers' classroom effectiveness as the most important factor in deciding whom to let go. 

Years of experience could only be considered to break a tie between teachers.

The bill would require the guidelines to be part of districts' policies beginning in 2016-17. 

The timing follows implementation next year of a statewide system for evaluating teachers based on their performance.

The state School Boards Association believes the bill is unnecessary since those guidelines are in its model policy, which most districts follow.

But senators want all districts to make decisions that way.