The 'belt of stability' is key in predicting the decay paths that unstable nuclides are likely to take.

Ths figure plots atomic number or proton number as the y value against neutron number as the x value. A colored dot is placed for each known nuclide. Stable nuclides are colored black. A decaying nuclide will undergo decay processes to move it toward the belt of black dots. Negatron decay is preferred by nuclides below and to the right -- because this decay process moves them up and to the left by one jump. Positron beta decay moves down and to the right; electron capture is 'equivalent' to this.