Zhang Nan will have his eye on history when the TOTAL BWF World Championships 2019 begin in Basel.

The Chinese great, should he capture the men’s doubles gold with Liu Cheng, will climb level on the all-time highest list with Park Joo Bong, Lin Dan and his former partner Zhao Yunlei as a five-time winner.

Still only 29, time is on Zhang’s side, but recent form is not. While Zhang/Liu have done little of note since the Fuzhou China Open last year – they were semifinalists – they will recall that their gold medal win in 2017, and their bronze medal last year were far from foregone conclusions, considering their average form in the run-up to both events. Zhang and Liu have qualified in ninth place on the rankings of the eligibility date (Tuesday 30 April 2019).

Nevertheless, Zhang and Liu will be in the shadow of compatriots Li Jun Hui and Liu Yu Chen, who have been able to strike form at big events. Their World Championships win last year was followed by their triumph at the high-profile HSBC BWF World Tour Finals, before they led China to the Sudirman Cup title.

Two other Chinese pairs have qualified – French Open champions Han Cheng Kai/Zhou Hao Dong and Fuzhou China Open runners-up He Ji Ting/Tan Qiang.

World No.1 duo Marcus Fernaldi Gideon and Kevin Sanjaya Sukamuljo are at the head of four Indonesian qualifiers. While the ‘Minions’ will be hoping to end their jinx at the Worlds, senior compatriots Mohammad Ahsan/Hendra Setiawan will be looking to push on with what has been a dream season so far. A win for the duo will see Setiawan draw level with former compatriot Liliyana Natsir and four others on four gold medals.

The other Indonesians hoping to make an impact will be Fajar Alfian/Muhammad Rian Ardianto and Berry Angriawan/Hardianto Hardianto.

Japan have never won a men’s doubles title at the Worlds and will be hoping one of their four pairs can make it this time – last year’s runners-up Takeshi Kamura/Keigo Sonoda; Asian champions Yuta Watanabe/Hiroyuki Endo; Takuto Inoue/Yuki Kaneko and Takuro Hoki/Yugo Kobayashi.

Among other big names are Denmark’s Kim Astrup/Anders Skaarup Rasmussen; Malaysia’s All England runners-up Aaron Chia/Soh Wooi Yik, Goh V Shem/Tan Wee Kiong and Ong Yew Sin/Teo Ee Yi; European Games champions Marcus Ellis/Chris Langridge, Russia’s Vladimir Ivanov/Ivan Sozonov and India’s Satwiksairaj Rankireddy/Chirag Shetty.

Japan are a formidable force in women’s doubles, and with four pairs having qualified within the top seven rankings, they will be confident of a strong show.

China have a balance of experience and youth. Resurgent pair Chen Qing Chen/Jia Yi Fan lead their challenge, backed by young stars Du Yue/Li Yin Hui; Li Wen Mei/Zheng Yu and Dong Wen Jing/Feng Xue Ying.

Korea will count on Lee So Hee/Shin Seung Chan and Kim So Yeong/Kong Hee Yong to repeat 1995 – when Gil Young Ah/Jang Hye Ock won Korea’s first – and only – women’s doubles title.

Europe’s contenders include Sara Thygesen/Maiken Fruergaard (Denmark), Anne Tran/Emilie Lefel (France), Selena Piek/Cheryl Seinen (Netherlands) and Chloe Birch/Lauren Smith (England), while Australia will be boosted by the recent Canada Open win of Gronya Somerville/Setyana Mapasa.

In mixed doubles, the form book is overwhelmingly in favour of China’s Zheng Si Wei/Huang Ya Qiong, who qualified in first place, followed by Wang Yi Lyu/Huang Dong Ping.

Among the few pairs to have beaten Zheng/Huang are Japan’s Yuta Watanabe/Arisa Higashino, Thailand’s Dechapol Puavaranukroh/Sapsiree Taerattanachai and Malaysia’s Chan Peng Soon/Goh Liu Ying, all of whom have qualified in the top five.

Puavarnukroh and Taerattanachai will take heart from their Singapore Open victory, while Chan/Goh will seek to build on the momentum from their title in New Zealand.

Two other Malaysian pairs – Goh Soon Huat/Shevon Jemie Lai and Tan Kian Meng/Lai Pei Jing – have also had encouraging performances this season.

Indonesia, recovering from the post-Liliyana Natsir era, have prominent names in Hafiz Faizal/Gloria Emanuelle Widjaja and Praveen Jordan/Melati Daeva Oktavianti, while England will sense a great opportunity this time, considering the form of European Games winners Marcus Ellis/Lauren Smith. Chris Adcock and Gabrielle Adcock haven’t had the best of seasons so far, and will hope they can turn it around in Basel.

Dutch duo Robin Tabeling/Selena Piek have hit the high notes since they came together this year; they were unbeaten in the Sudirman Cup and could cause damage to bigger reputations.

Other pairs, such as Germany’s Marvin Seidel/Linda Efler and Mark Lamsfuss/Isabel Herttrich; India’s Satwiksairaj Rankireddy/Ashwini Ponnappa, Denmark’s Niclas Nohr/Sara Thygesen and Chinese Taipei’s Wang Chi-Lin/Cheng Chi Ya could also cause ripples in the draw.