Roger Federer leans on recent history for Novak Djokovic semi-final

• Swiss beat Djokovic in last meeting, in ATP Tour Finals
• That win ‘showed me he is beatable’, Federer saysRoger Federer has returned from hell twice this week, yet he is still smiling, refusing to panic, and says: “I believe until the end.” Even the 38‑year‑old Swiss does not know when that dreaded moment will arrive but he remains convinced, against growing evidence, there is a little piece of heaven waiting for him here on Sunday. Related: Rafae