The phrase "a strong rival for" is correct and usable in written English.
It can be used when discussing competition between entities, such as companies, athletes, or products, indicating that one is a formidable competitor to another.
Example: "The new smartphone model is a strong rival for the leading brand in the market."
Alternatives: "a formidable competitor to" or "a tough contender against".
They continued: "They agreed that Kim Jong-il's brother-in-law Jang Song-taek would prove a strong rival for the younger Kim and would probably be tempted to challenge him.
That Hyundai has the resources to renew its cars so frequently must surely terrify the competition; the current Skoda Octavia, for example, a strong rival for the i30 in the emerging brands sub-category of the Focus class, has been around in the UK since mid-2004, and there is no successor in sight.
Greatly admired at Cannes, where Pawlikowski took home the director prize, "Cold War" also dominated the recent European Film Awards (winning for film, director, actress and others) and has emerged as a strong rival for "Roma" in this year's foreign language Oscar race.
Perhaps this is the real worry of the Chinese administration: that efforts to restrict the power and reach of Islam in Xinjiang have made it a stronger rival for the domination of public space.
Most observers expected Song to become premier of a new cabinet and a strong rival of Yuan for power.
The simple and transparent pricing even enables Wealthfront to become a strong rival of the traditional banking industry.
Alibaba is betting that pairing Koubei with Ele.me, throwing in a couple of billion and adding a dash of SoftBank can give it a strong rival that can compete for China's 'online to offline' market.
He said: "The win was a great way to set ourselves up for the title presentation, with three points, a clean sheet and three goals against a strong rival and I am delighted for all of the players and staff of the club that they managed to have a fantastic day.
AirTran Airways, already a strong rival to US Airways and Delta Air Lines on the East Coast, is poised for such a move, analysts say.
The Judiciary Committee chairman began the hearings as a contender for the Democratic Presidential nomination - not the leader, but a strong rival who was raising money and drawing crowds.
