Ngicela unginikeze isifinyezo semithetho yamanje ye-roller derby.
Context:I-roller derby idlalwa ngezikhathi ezimbili zemizuzu engu-30.: 4 Amaqembu amabili adlala kuze kube ngabadlali abangu-15 ngalinye lidlala amalungu afinyelela kwayisihlanu ngeziqephu ezibizwa ngokuthi "ama-jams". Ama-jams ahlala imizuzu emibili ngaphandle kokuba aqedwe ngaphambi kwesikhathi.: 5 Ithimba ngalinye likhetha umdlali obhala amaphuzu ("i-jammer"); amanye amalungu amane "abavimbeli". Umgqugquzeli oyedwa angabekwa njenge-"pivot" - umgqugquzeli ovunyelwe ukuba ngumgqugquzeli ngesikhathi sokudlala.: 7 Umgqugquzeli olandelayo ungabandakanya abadlali abahlukile kubadlali be-15 abasohlwini, nokukhethwa okuhlukile kwe-jammer ne-pivot.: 7   Phakathi nesikhathi ngasinye sokushayisana, abadlali bashushuluza ngokuphambene nesimiso sewashi emzileni wesekethe. Amaphuzu atholakala kuphela uma ithimba liphazamisa. Ngemuva kokweqa i-pack bese ugingqa isiyingi esisodwa ukuqala olunye "uhambo" nge-pack, i-jammer ithola iphuzu elilodwa lokudlula noma yimuphi umvimbi ophikisayo.: 33 [note 1] Imithetho ichaza ukudlula "okuzuziwe"; ikakhulukazi, i-jammer kumele ibe ngaphakathi kwemingcele futhi iqonde. I-jammer's first earned pass ihola iphuzu lokudlula lowo ovimbelayo nephuzu ngalinye lomphikisi ovimbelayo ongekho emzileni (ngokwesibonelo, osebenzisa inhlawulo, noma lapho umphikisi engatholanga abadlali abahlanu abazofaka i-jam). Uma i-jammer idlula lonke iphakethe, kuyindlela yokuthola amaphuzu amane, evame ukubizwa ngokuthi "i-grand slam". [note 1]  Abavimbeli beqembu ngalinye basebenzisa ukuthintana komzimba, ukushintsha izikhundla, namanye amaqhinga ukusiza i-jammer yabo ukuba ibhale amaphuzu ngenkathi iphazamisa i-jammer yeqembu eliphikisayo.
Umncintiswano we-roller derby unezingxenye ezimbili zemizuzu engu-30. Abadlali bazobe besendleleni isikhathi esiyimizuzu emibili. Iqembu ngalinye lizoba nabadlali abahlanu ngesikhathi esisodwa. Abadlali abane abavela eqenjini ngalinye bakhethwa ukuba babe abavimbelayo, futhi bazodlala kokubili ukuhlasela nokuvikela ngesikhathi esifanayo. Iqembu ngalinye lizobeka umphazamisi oyedwa ongumdlali oyinhloko wokushaya amaphuzu. Abaphazamisi bathola amaphuzu ngokudlula abavimbela iqembu eliphikisayo.