The biggest improvement in the past few years was deep neural networks. These were behind Google Brain and Microsoft's Adam: http://www.wired.com/2013/02/andro

The biggest improvement in the past few years was deep neural networks. These were behind Google Brain and Microsoft's Adam: http://www.wired.com/2013/02/android-neural-network/ http://www.wired.com/2013/02/android-neural-network/ http://www.wired.com/2014/07/microsoft-adam/ http://www.wired.com/2014/07/microsoft-adam/