In ten NL seasons, the slick-fielding Dunlap at various times led NL second basemen in all fielding categories and twice batted over .300. But his greatest year was 1884 when, playing for powerhouse St. Louis in the short-lived Union Association, he led UA second basemen in all five fielding categories while leading the league in BA (his .412 was 52 points above that of the next-best hitter), slugging (.621), runs (160), and HR (13). His 160 runs scored set a new ML record, and still rank fourteenth-best of all time.