Box-office forecasters are hedging their bets when it comes to predicting the probable top film this weekend. Three films are opening in wide release, The Lincoln Lawyer, starring Matthew McConnaughey, Limitless , starring Bradley Cooper, and Paul, starring a CGI extraterrestrial voiced by Seth Rogen. Virtually all of the box-office prognosticators are predicting that the race will be tight. They're also predicting that none of the films will cross the $20-million mark (with most indicating that they'll be lucky to take in $15 million). All three will be up against two solid holdovers, the second week of Battle Los Angeles and the third week of Rango. The Lincoln Lawyer may have a slight edge, given the fact that the studio, Lionsgate, teamed up with Groupon in a special promotion in which tickets were offered for 48 hours at huge discounts. Neither the studio nor Groupon has indicated how many tickets were distributed via the promotion, but the Hollywood Reporter said that Lionsgate is "subsidizing" the promotion -- presumably meaning that it will pay theaters the difference between the Groupon price and the price at the ticket booth so that grosses will reflect the full price.