Who will replace Alesha Dixon? With Alesha Dixon's defection to ITV, there is a vacant gold chair behind the Strictly Come Dancing judging table. A set of spare scoring paddles to be wielded with a flourish. A squidgy space on Claudia Winkelman's Sunday night banqette. Speculation is already rife on who will replace Dixon, so let's examine the runners and riders. With three men already on the panel (barring any other departures or Len Goodman taking retirement), the newcomer is bound to be female. This rules out the likes of Jason Gardiner, who until this year has played the panto villain role on Dancing On Ice, or one of the male professionals, notably Anton Du Beke. There will be an inevitable campaign to bring back Arlene Philips, but she'd surely have more pride than that. Her return would also be a tacit admission that the producers made a mistake three years ago. Ballerina Darcey Bussell and Dirty Dancing star Jennifer Grey have both been guest judges before. Grey is a hit on the US version, Dancing with The Stars, but fell flat when she filled in for Len Goodman here in November. Bussell would be the better full-time choice but not exactly a populist name - she's more BBC Two than primetime BBC One. Other names being touted include former ladette, Zoe Ball, a finalist in 2005 and current host of weeknight spin-off show It Takes Two, and 2010 champion Kara Tointon - but either would face the same problems as Dixon. Tointon's boyfriend Artem Chigvintsev is also one of the professional dancers, so there is conflict of interest. Monica Mason retires from the Royal Ballet next year, but would be an even more highbrow option than Bussell. Hip-hop choreographer Kate Prince and dancer-cum-actress Nicole Sherwin are being tipped for big things, but likely to start lower down the TV ladder. This all means that my tip, and the early favourite of many bookmakers, is Karen Hardy. The 41-year-old is an ex-professional who now runs her own dance school - like a mini-Goodman. She provided the red button commentary during the recent series, a sign that she's being groomed for a bigger role. Her appearances on It Takes Two have also impressed, as she picks apart the previous weekend's routines with wit and insight. However, Hardy is hardly a household name. The Beeb may yet opt for someone younger or bigger-profile to deliver glamour and headlines. With Strictly on a high after a hit year, it's a tough call. As Craig Revel Horwood might put it: "One word, three syllables, darling: diff-i-cult."