An analysis of the dynamics of challenger quality across states reveals some interesting patterns. Do some states consistently recruit greater proportions of high-quality challengers in elections for the US House of Representatives while other states do so less frequently? If so, what explains this variation? This chapter aims to answer this question by examining state-level variation in mean aggregate levels of high-quality challengers. It demonstrates substantial variation across states with respect to the overall level of challenger quality in US House elections between 1972 and 2018. The results of the bivariate analysis indicate that the proportion of high-quality challengers in states with strong party competition is somewhat higher than the proportion we observe in states with weak party competition. The hypothesis is that greater state legislative professionalization should yield lower overall levels of experienced challengers in House elections.