WELLINGTON: New Zealand’s world number one Lydia Ko has “hit the panic button” by sacking her caddie in response to a form slump, high-profile bagman Steve Williams said Wednesday. Ko’s Australian caddie Jason Hamilton confirmed this week that he had parted ways with the 19-year-old after almost two years together. “She felt like now was a good time to make a change,” Hamilton told golfchannel.com. “She said she thought it would be good to get a different set of eyes out there.” After rewriting the amateur record books, Ko enjoyed a dream start to her professional career and claimed 14 LPGA titles, including two majors. But the Korean-born Kiwi’s form has faltered lately and she finished 51st in the Korea LPGA Championship that wrapped up on Sunday.