The Improbable Theory of Ana and Zak

http://hip1.sjvls.org/ipac20/ipac.jsp?session=C43PT59191779.74930&menu=search&aspect=subtab255&npp=20&ipp=20&spp=100&profile=thq&ri=7&source=~!horizon&index=.TW&term=The+Improbable+Theory+of+Ana+and+Zak&x=17&y=15&aspect=subtab255The Improbable Theory of Ana and Zak by Brian Katcher 

Ana is an honor student obsessed with being successful at everything academic, Clayton is her thirteen-year-old genius brother, the youngest student in their high school and Zak is gamer who is forced to join the quiz team by his teacher--but when Clayton sneaks off to a science fiction convention in Seattle while they are all there for a quiz bowl tournament, Ana is forced to rely on the unreliable Zak to find him.