One of the four elements in legal malpractice is “ascertainable damages.”  They are more easily provable in some settings than in others.  Custody and matrimonial economic damages are very hard to demonstrate, as Miazga v Assaf  2016 NY Slip Op 01025  Decided on February 11, 2016
Appellate Division, Third Department shows us.

“Plaintiff retained defendants in January 2011 to represent him in a custody proceeding and, thereafter, in a divorce action. In April 2012, after a breakdown in the parties’ relationship, defendant Michael D. Assaf requested that defendants be relieved as plaintiff’s counsel and, after a hearing, the application to withdraw was granted. Plaintiff proceeded pro se in his divorce action and custody proceeding and, thereafter, commenced this action against defendants. In his complaint, plaintiff alleges, among other things, nine causes of action with respect to defendants’ representation, including, among other things, breach of a fiduciary duty, legal malpractice, defamation and breach of contract. Defendants asserted a counterclaim for, among other things, unpaid legal fees. Defendants moved for summary judgment dismissing the complaint, which plaintiff opposed. Plaintiff also cross-moved seeking partial judgment on the issue of liability for the disclosure of an allegedly privileged confidential email, among other things. Supreme Court granted defendants’ motion for summary judgment with respect to plaintiff’s claims of legal malpractice and breach of a fiduciary duty, [*2]fraud, defamation and failure to communicate, but denied the motion regarding plaintiff’s breach of contract claim with respect to defendants’ billing rates. Supreme Court also denied plaintiff’s cross motion. Plaintiff then moved to reargue and/or renew, in addition to moving for Supreme Court’s recusal. Supreme Court denied plaintiff’s motion, adhering to its original order. Plaintiff now appeals from both orders,^[FN1] and defendants cross-appeal from that part of Supreme Court’s order as denied their motion for summary judgment dismissing the complaint ^[FN2]. We affirm both orders.”

“Here, defendants have sufficiently demonstrated that plaintiff was unable to prove actual and ascertainable damages relating to Assaf’s representation. Specifically, in the affirmation in support of the motion for summary judgment, defense counsel points out that, despite repeated requests, plaintiff never produced evidence supporting the damages that he specified in his bill of particulars and, therefore, failed to show that any such losses occurred. As such, we agree that defendants carried their burden of producing competent evidence sufficient to shift the burden to plaintiff to raise a triable issue of fact. For his part, plaintiff claims that he incurred damages including, but not limited to, $55,000 in fees to defendants, payment of experts, $20,000 in expenses, an unspecified amount of lost income and the amount of money “expended to overcome [defendants’] actions.” However, absent any proof of same in the record, these statements remain speculative assertions, which are insufficient to defeat a motion for summary judgment (see Place v Grand Union Co., 184 AD2d 817, 817 [1992])^[FN5]. Thus, plaintiff failed to meet his shifted burden.

Further, setting aside plaintiff’s inability to raise an issue of fact with respect to the element of damages, summary judgment remains an appropriate remedy here inasmuch as plaintiff is also unable to sufficiently demonstrate that he would have been successful on the merits of his underlying action. In support of his opposition, plaintiff provided an affirmation by an expert, who stated that it is “arguable” that the custody matter would have been resolved more quickly had depositions occurred earlier. However, the expert could not state that plaintiff would have been ultimately successful. Thus, because plaintiff failed to produce evidence suggesting that, but for Assaf’s actions or inaction, the underlying matrimonial litigation would have resulted in a more favorable outcome (see Marchell v Littman, 107 AD3d 1082, 1084 [2013], lv denied 22 NY3d 856 [2013]; Sevey v Friedlander, 83 AD3d at 1227), Supreme Court properly granted defendants’ motion for summary judgment with respect to plaintiff’s legal malpractice claim.