Trial court’s summary denial of petition for resentencing, based on defendant’s ineligibility under the Strike Reform Act of 2012, is an appealable order. In 1996, Teal was convicted of making criminal threats (Pen. Code, § 422); two strike priors were found true. He received a life Three Strikes sentence. After passage of Proposition 36, the Strike Reform Act, Teal sought resentencing. The trial court denied the petition because Teal’s commitment offense is a serious felony. He appealed. The Court of Appeal found the order not appealable, treated the case as a petition for writ of mandate and denied it. The Supreme Court granted review. Held: Reversed. The right to appeal is statutory. The Strike Reform Act does not address whether the denial of a petition for resentencing is appealable, but under Penal Code section 1237, subdivision (b), a defendant may appeal an order after judgment affecting his substantial rights. A petitioner has standing to file a petition and to have a court determine his eligibility for resentencing because a justiciable controversy exists in which the petitioner has a beneficial interest. Teal filed a timely petition claiming he was entitled to be resentenced because criminal threats was not a serious felony in 1996, when he was convicted. The trial court’s authority to decide his petition did not rest on his eligibility to file the petition. Section 1170.126, subdivision (f) requires the trial court to determine the petitioner’s eligibility for resentencing upon receiving a recall petition. Thus, section 1170.126 creates a substantial right to seek resentencing, the denial of which forecloses a reduced sentence, thereby affecting the substantial rights of the petitioner.