Midterm elections upon us, most observers expect Republicans to take over the House of Representatives, though projections vary widely as to how many seats they’ll gain, and a massive number of races – more than 100 – are close enough to go either way. The magic number Republicans need to gain to take control: 39. So how can an Election Night observer get a sense of the big picture amid the many returns coming in? Rather than zeroing in on any individual race, look for trends in those expected to be closest. Here are a handful of races to keep an eye on in the states with early-closing polls.