Centers as a designator/concept.  See http://www.lynette.org/dconcepts.html

XXX: add bounce the centers from rh two faced lines
XXX: add centers r&l thru from facing lines
XXX: add own the centers, belles run by crossover circ from rh two-faced lines
XXX: add centers, beaus run from lines facing out
XXX: add echo centers, r&l thru from lines facing out
XXX: add centers work tandem, hinge from r-h columns
XXX: add centers tandem hinge from r-h columns (ends don't move)
XXX: centers work stable, shazam (four closest to center) from rh tidal wave
XXX: each wave, centers work stable, shazam (centers on each side) from rh tidal

sdr> /program = Program.PLUS ; setFormation(Formation.SQUARED_SET)
|      3Gv  3Bv
| 
| 4B>            2G<
| 
| 4G>            2B<
| 
|      1B^  1G^
sdr> heads lead right
| 4B>  3G<  1B>  2G<
| 
| 4G>  3B<  1G>  2B<
sdr> extend
| 4B>  1B>
| 
| 3G<  2G<
| 
| 4G>  1G>
| 
| 3B<  2B<
sdr> fan the top
| 3B^  4Gv  3G^  4Bv  2B^  1Gv  2G^  1Bv
sdr> centers run
| 4G^  3B^  4Bv  3Gv  1G^  2B^  1Bv  2Gv
sdr> centers cross run
| 4B^  4G^  3Gv  3Bv  1B^  1G^  2Gv  2Bv
sdr> /exit